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<?xml version="1.0"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://docbook.org/xml/4.2/docbookx.dtd"
[
<!ENTITY evers "1.1.0">
<!ENTITY evmsugchap1 SYSTEM "over-ug.xml">
<!ENTITY evmsugpref SYSTEM "pref-ug.xml">
<!ENTITY evmsuginstall SYSTEM "install-ug.xml">
<!ENTITY evmsuglocating SYSTEM "locatingdev-ug.xml">
<!ENTITY evmscmuse SYSTEM "cmuse-ug.xml">
<!ENTITY evmsmigrate SYSTEM "migrateto-ug.xml">
<!ENTITY evmsassignseg SYSTEM "assignseg-ug.xml">
<!ENTITY evmscreateseg SYSTEM "create-seg.xml">
<!ENTITY evmscreatecont SYSTEM "create-cont.xml">
<!ENTITY evmscreatereg SYSTEM "create-reg-ug.xml">
<!ENTITY evmscmuse SYSTEM "cmuse-ug.xml">
<!ENTITY evmscreatevol SYSTEM "createvol-ug.xml">
<!ENTITY evmsconvert SYSTEM "convertto-ug.xml">
]>
<book>
<bookinfo><title>EVMS User Guide</title>
<authorgroup><author><firstname>Joy</firstname>
<surname>Goodreau</surname>
<affiliation><orgname>IBM</orgname></affiliation></author>
<author><firstname>Kylie</firstname>
<surname>Smith</surname>
<affiliation><orgname>IBM</orgname></affiliation></author></authorgroup>
<pubdate>October 21, 2002</pubdate>
<copyright><year>2002</year>
<holder>IBM</holder></copyright>
<legalnotice><title>Special Notices</title>
<para>The following terms are registered trademarks of International Business Machines corporation in the United States and/or other countries: AIX, OS/2, System/390. A full list of U.S. trademarks owned by IBM may be found at <ulink url="http://www.ibm.com/legal/copytrade.shtml">http://www.ibm.com/legal/copytrade.shtml</ulink>.</para>
<para>Intel is a trademark or registered trademark of Intel Corporation in the United States, other countries, or both.</para>
<para>Windows is a trademark of Microsoft Corporation in the United States, other countries or both. </para>
<para> Linux is a trademark of Linus Torvalds. </para>
<para>Other company, product, and service names may be trademarks or service marks of others.</para>
<para>This document is provided &quot;AS IS,&quot; with no express or implied warranties. Use the information in this document at your own risk. </para>
</legalnotice>
<legalnotice><title>License Information</title>
<para>This document may be reproduced or distributed in any form without prior permission provided the copyright notice is retained on all copies. Modified versions of this document may be freely distributed provided that they are clearly identified as such, and this copyright is included intact. </para></legalnotice>
</bookinfo>
&evmsugpref;
&evmsugchap1;
&evmsuginstall;
&evmsuglocating;
&evmscmuse;
&evmsmigrate;
&evmsassignseg;
&evmscreateseg;
&evmscreatecont;
&evmscreatereg;
&evmscreatevol;
&evmsconvert;
</book>

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<chapter id="evmsassignseg"><title>Assigning a Segment Manager</title>
<para> This chapter discusses when to use a segment manager, what the different types of segment managers are, and how to assign a segment manager to a disk. </para>
<sect1 id="whenassign"><title>When to Assign a Segment Manager</title>
<para>Assigning a segment manager to a disk allows the disk to be subdivided into
smaller storage objects called disk segments. The assign command causes a
segment manager to create appropriate metadata and expose freespace that the segment manager
finds on the disk. You will need to assign segment managers when you have a new disk or
when you are switching from one partitioning sheme to another. </para>
<para>EVMS displays disk segments as the following types: </para>
<itemizedlist><listitem><para>Data: a set of contiguous sectors that has been allocated
from a disk and can be used to construct a volume or object.</para></listitem>
<listitem><para>Freespace: a set of contiguous sectors that are unallocated
or not in use. Freespace can be used to create a segment.</para></listitem>
<listitem><para>Metadata: a set of contiguous sectors that contain
information needed by the segment manager.</para></listitem>
</itemizedlist>
</sect1>
<sect1 id="smtypes"><title>Types of Segment Managers</title>
<para>There are three types of segment managers in EVMS: DOS, GPT, and S/390. </para>
<sect2 id="defaultseg"><title>DOS Segment Manager</title>
<para>The most
commonly used segment manager is the DOS Segment Manager. This plug-in
provides support for traditional DOS disk partitioning. The
DOS Segment Manager also recognizes and supports the following variations
of the DOS partitioning scheme:
<itemizedlist><listitem><para>OS/2: an OS/2 disk has additional metadata
sectors that contain information needed to reconstruct disk segments.</para></listitem>
<listitem><para>Embedded partitions: support for BSD, SolarisX86, and UnixWare
is sometimes found embedded in primary DOS partitions.
The DOS Segment Manager recognizes and supports these
slices as disk segments.</para></listitem></itemizedlist></para>
</sect2>
<sect2 id="gptseg"><title>GUID Partitioning Table (GPT) Segment Manager</title>
<para>The GUID Partitioning Table (GPT) Segment Manager handles the
new GPT partitioning scheme
on IA-64 machines. The Intel
<citetitle>Extensible Firmware Interface Specification</citetitle>
requires that firmware be able to discover partitions and produce logical devices that
correspond to disk partitions. The partitioning scheme described in
the specification is called GPT due to the extensive use of
Globally Unique Identifier (GUID) tagging. GUID is a 128 bit long
identifier, also referred to as a Universally Unique Identifier (UUID).
As described in the Intel <citetitle>Wired For Management Baseline Specification</citetitle>,
a GUID is a combination of time and space fields that produce an
identifier that is unique across an entire UUID space.
These identifiers are used extensively on GPT partitioned disks
for tagging entire disks and individual partitions.
GPT partitioned disks serve several functions, such as:</para>
<itemizedlist>
<listitem><para>keeping a primary and backup copy of metadata</para>
</listitem>
<listitem><para>replacing msdos partition nesting by allowing many partitions</para>
</listitem>
<listitem><para>using 64 bit logical block addressing</para>
</listitem>
<listitem><para>tagging partitions and disks with GUID descriptors</para>
</listitem>
</itemizedlist>
<para>The GPT Segment Manager scales better to large disks. It provides more redundancy with added reliability and uses unique names. However, the GPT Segment Manager is not compatible with DOS, OS/2, or Windows&reg;. </para></sect2>
<sect2 id="s390sm"><title>S/390 Segment Manager</title>
<para>The S/390 Segment Manager is used exclusively on System/390
mainframes. The S/390 Segment Manager has the ability to recognize
various disk layouts found on an S/390 machine, and provide
disk segment support for this architecture. The two most common disk
layouts are Linux Disk Layout (LDL) and Common Disk Layout (CDL). </para>
<para>The principle difference between LDL and CDL is that an LDL disk
cannot be further subdivided. An LDL disk will produce a single metadata
disk segment and a single data disk segment. There is no freespace on an
LDL disk, and you cannot delete or re-size the data segment. A CDL disk can
be subdivided into multiple data disk segments
because it contains metadata that is missing from an LDL disk, specifically
the Volume Table of Contents (vtoc) information.</para>
<para>The S/390 Segment Manager is the only segment manager plug-in
capable of understanding the unique S/390 disk layouts. The S/390 Segment Manager
cannot be assigned or unassigned from a disk. </para></sect2>
</sect1>
<sect1 id="assignsegex"><title>Assigning a Segment Manager to an Existing Disk</title>
<para>When you assign a segment manager to a disk, the segment manager will need to change the basic
layout of the disk. This change means that some sectors will be reserved for metadata and the remaining sectors will
be made available for creating data disk segments. Metadata sectors are written to disk to save information
needed by the segment manager; previous information found on the disk is lost. Before assigning a
segment manager to an existing disk, you must remove any existing volume management structures including any
previous segment manager.</para>
</sect1>
<sect1 id="assignsegnew"><title>Assigning a Segment Manager to a New Disk</title>
<para>When a new disk is added to a system,
the disk usually contains no data and has not
been partitioned. If this is the case, the disk will show up in EVMS as a compatibility volume because
EVMS cannot tell if the disk is being used as a volume. To assign a segment manager to the disk so that it
can be subdivided into smaller disk segment objects, tell EVMS that the disk is not a
compatibility volume by deleting the volume information.</para>
<para>If the new disk was moved from another system, chances are good that the disk already contains
metadata. If the disk does contain metadata, the disk will show up in EVMS with storage objects that
were produced from the existing metadata. Deleting these objects will allow you to assign a different
segment manager to the disk, and you will lose any old data. </para>
</sect1>
<sect1 id="assignex"><title>Working through an Example</title>
<para>This section provides a detailed explanation of how to assign a segment manager with EVMS by
working through the scenario below.</para>
<para>EVMS initially displays the
physical disks it sees as volumes. Assume that you have added a new disk to the system that EVMS
sees as sde. This disk contains no data and has not been subdivided (no partitions). EVMS assumes that this
disk is a compatibility volume known as <filename>/dev/evms/sde</filename>. </para>
<blockquote><example><title>Assign the DOS Segment Manager</title>
<para>Assign the DOS Segment Manager to disk sde. </para></example></blockquote>
<note><title>NOTE</title>
<para>In the example above, the DOS Segment
Manager creates two segments on the disk:
a metadata segment known as sde_mbr, and a
segment to represent the available space on
the drive, sde_freespace1. This freespace
segment (sde_freespace1) can be divided into
other segments because it represents space on
the drive that is not in use. </para></note>
<sect2 id="assignseggui"><title>Using the EVMS GUI</title>
<para>To assign the DOS Segment Manager to sde, you will first need to remove the volume, <filename>/dev/evms/sde</filename>:</para>
<orderedlist>
<listitem><para>Select <menuchoice><guimenu>Actions</guimenu>
<guimenuitem>Delete</guimenuitem>
<guimenuitem>Volume</guimenuitem></menuchoice>.</para></listitem>
<listitem><para>Select <filename>/dev/evms/sde</filename>.</para></listitem>
<listitem><para>Click <guibutton>Delete</guibutton>.</para></listitem>
</orderedlist>
<para>Once the volume is removed, assign the DOS Segment Manager:</para>
<orderedlist>
<listitem><para>Select <menuchoice><guimenu>Actions</guimenu>
<guimenuitem>Add</guimenuitem>
<guimenuitem>Segment Manager to Storage Object</guimenuitem></menuchoice>.</para></listitem>
<listitem><para>Select <guilabel>DOS Segment Manager</guilabel>.</para></listitem>
<listitem><para>Click <guibutton>Next</guibutton>.</para></listitem>
<listitem><para>Select <guilabel>sde</guilabel></para></listitem>
<listitem><para>Click <guibutton>Add</guibutton></para></listitem>
</orderedlist>
</sect2>
<sect2 id="assignsegncur"><title>Using Ncurses</title>
<para>To assign the DOS Segment Manager to sde, you will first need to remove the volume, <filename>/dev/evms/sde</filename>.</para>
<orderedlist><listitem><para>Press <keycap>2</keycap> to view volumes.</para></listitem>
<listitem><para>Highlight <filename>/dev/evms/sde</filename> by using the <keycap>up</keycap>
and <keycap>down</keycap> arrow keys. Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <guilabel>Delete Volume</guilabel>. Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <guilabel>Delete</guilabel>. Press the <keycap>Enter</keycap> key.</para></listitem>
</orderedlist>
<para>Once the volume is removed, assign the DOS Segment Manager:</para>
<orderedlist>
<listitem><para>Press <keycap>4 </keycap> to switch views.</para></listitem>
<listitem><para>Highlight <guilabel>Logical Disk</guilabel>. Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Press the <keycap>Enter</keycap> key to see the context sensitive menu. </para></listitem>
<listitem><para>Highlight <guilabel>Assign Segment Manager to Disk</guilabel>.
Press the <keycap>Enter</keycap> key. </para></listitem>
<listitem><para>Highlight <guilabel>DOS Segment Manager</guilabel>. Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <guilabel>sde</guilabel>. Press the <keycap>spacebar</keycap>
to select then press the <keycap>Enter</keycap> key to continue.</para></listitem>
<listitem><para>Press the <keycap>Enter</keycap> key to select the default settings. </para></listitem>
</orderedlist>
</sect2>
<sect2 id="assignsegcli"><title>Using the CLI</title>
<para>To assign the DOS Segment Manager to sde, first tell EVMS that this disk is not a
volume and is available for use:</para>
<programlisting>Delete:/dev/evms/sde</programlisting>
<para>Next, assign the DOS Segment Manager to sde by typing the following:</para>
<programlisting>Assign:DosSegMgr={},sde</programlisting>
</sect2>
</sect1>
</chapter>

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<chapter id="evmscmuse"><title>Using the EVMS Interfaces</title>
<para>The following chapter explains how to use the EVMS GUI, Ncurses, CLI interfaces, and the EVMS emulation of the Linux LVM command set . This section includes basic navigation and commands. </para>
<sect1 id="GUI"><title>EVMS GUI</title>
<para>The EVMS GUI provides you with a flexible and easy-to-use
interface to administer volumes and storage objects. Many users will find the EVMS GUI easy to use because it checks which
storage objects, actions, and plug-ins are acceptable for each
task. </para>
<sect2 id="GUITASKS"><title>Using Context Sensitive and Action Menus</title>
<para>In the EVMS GUI you can accomplish most
tasks in one of two ways: context sensitive menus and the
<guimenu>Actions</guimenu> menu.</para>
<para>Context sensitive menus are available from any
of the main "views." Each view corresponds to a
page in a notebook widget located on the EVMS
GUI main window. These views are made up of different
trees or lists that visually represent the organization of
different object types, such as volumes,
feature objects, regions, containers, segments, or disks. </para>
<para>You can view the context
sensitive menu for an object by right-clicking on that
object. The actions that are available
for that object will appear on
the screen. The GUI will present only actions that are acceptable
for that object at that point in the process. These actions will not always be a complete set. </para>
<para>To use the <guimenuitem>Actions</guimenuitem> menu
choose <menuchoice>
<guimenuitem>Action</guimenuitem>
<guimenuitem>&lt;the action you want
to accomplish&gt;</guimenuitem>
<guimenuitem>&lt;options&gt;</guimenuitem></menuchoice>.
The <guimenuitem>Actions</guimenuitem> menu provides a more guided path to
completing a task than context sensitive menus do. The
<guimenu>Actions</guimenu> option is similar to the popular wizard or druid
approach used by many GUI applications.</para>
<para>All of the operations you need to
perform as an administrator are available through
the <guimenuitem>Actions</guimenuitem> menu.</para>
</sect2>
<sect2 id="COMMIT"><title>Saving Changes</title>
<para>All changes you make while in the EVMS
GUI are only in memory until you save the changes.
In order to make your changes
permanent, you must save
all changes before exiting. If you
forget to save the changes and decide to exit or close the
EVMS GUI, you will be reminded about
saving any pending changes.</para>
<para>To explicitly save all changes you
made, select <menuchoice><guimenu>Action</guimenu>
<guimenuitem>Save</guimenuitem></menuchoice>, and click
the <guibutton>Save</guibutton> button.</para>
</sect2>
<sect2 id="refresh"><title>Refreshing Changes</title>
<para>The <guibutton>Refresh</guibutton> button updates the view but does not cause a rediscover. Clicking
the <guibutton>Refresh</guibutton> button allows you to see changes, like mount points, that you might have mounted outside of the GUI.</para></sect2></sect1>
<!-- NCurses -->
<sect1 id="NCURSES"><title>EVMS Ncurses Interface</title>
<para>The EVMS Ncurses (evmsn) user interface provides a menu driven
interface with similar characteristics to the EVMS GUI. Like the EVMS GUI,
evmsn can accommodate new plug-ins and features without requiring any code
changes.</para>
<para>The availability of an EVMS Ncurses user interface
allows you to manage volumes on systems that do not have the X
and GTK+ libraries that are required by the EVMS GUI.</para>
<sect2 id="NCURSESOVER"><title>Navigating through EVMS Ncurses</title>
<para>The EVMS Ncurses user interface initially
displays a list of logical volumes similar to the
logical volumes view in the EVMS GUI.</para>
<para>A general guide to navigating through the layout of the
Ncurses screen is listed below:</para>
<itemizedlist>
<listitem><para>A menu of key-to-action mappings is
listed at the bottom of the screen.</para></listitem>
<listitem><para>The <keycap>2</keycap> key returns you to the
volumes view.</para></listitem>
<listitem><para>The <keycap>4</keycap> key displays a menu of
other views you could switch
to.</para></listitem>
<listitem><para>The <keycap>5</keycap> key saves changes made
during an evmsn session.</para></listitem>
<listitem><para>The <keycap>9</keycap> key exits Ncurses.</para></listitem>
<listitem><para>Status messages and user
prompts appear on a line located
between the window frame for the current view and the action
keys menu line.</para></listitem>
<listitem><para>You can select which actions to
perform by using the <keycap>up</keycap> and
<keycap>down</keycap> arrow keys to highlight
an object within the current view. After the
correct item is highlighted, press the <keycap>Enter</keycap>
key. Ncurses will typically provide a context
sensitive sub-menu of available actions.</para> </listitem>
<listitem><para>When navigating from one menu
to another, the <keycap>Esc</keycap> (escape) key will return
you to the previous menu.</para> </listitem>
</itemizedlist>
<para>Ncurses allows you to create new
objects based on your current view. For example, a container can be created
in the Storage Containers view by selecting any
container. If the view
is empty, you can still create a container by pressing the
<keycap>Enter</keycap> key on the
"No Storage Containers found" row.</para>
<para> In order to change or set an option value
within the configuration options menu, use the <keycap>spacebar</keycap> key to
select the value. Press
<keycap>Enter</keycap> when you are finished. In order to
complete most operations you must press <keycap>Enter</keycap>.</para>
</sect2>
<sect2 id="NCURCHANGES"><title>Saving Changes</title>
<para>All changes you make while in the EVMS
Ncurses are only in memory until you save the changes.
In order to make your changes permanent, you must save
all changes before exiting. If you
forget to save the changes and decide to exit or close the
EVMS Ncurses, you will be reminded about
saving any pending changes.</para>
<para>To explicitly save all changes you
made, press the <keycap>5</keycap> key and confirm
that you want to save changes.</para>
</sect2>
</sect1>
<!-- CLI Commands -->
<sect1 id="COMMANDLINE"><title>EVMS Command Line Interpreter</title>
<para>The EVMS Command Line Interpreter (EVMS CLI) provides a
command-driven user interface for EVMS. The EVMS CLI is
designed to help automate volume management tasks. For
situations where the EVMS GUI is not available, the EVMS CLI
provides an interactive mode.</para>
<para>Because the EVMS CLI is an interpreter, it operates
differently than command line utilities for the
operating system. The options you specify
on the EVMS CLI command line used to invoke the EVMS
CLI control how the EVMS CLI operates. For example, the
command line options tell the CLI where to go for commands to interpret and how
often the EVMS CLI should commit changes to disk.
When invoked, the EVMS CLI prompts for commands. </para>
<para>The volume management commands the EVMS CLI understands
are specified in the <filename>/usr/src/evms-1.2.0/engine/UserInterface/commandline/grammar.ps</filename>
file that accompanies the EVMS
package. These commands are described in detail in the EVMS
man page, and help on these commands is available from the EVMS
CLI itself. </para>
<sect2 id="CLITASKS"><title>Using the EVMS CLI</title>
<para>Use the <command>evms</command> command to start
the EVMS CLI. If you do not enter an option with
<command>evms</command>, the EVMS CLI will start in
interactive mode. In interactive mode, the EVMS CLI prompts
you for commands. The results of each command are saved
to disk immediately. The EVMS CLI will exit when you type <userinput>exit</userinput>.
You can modify this behavior by using
the following options with <command>evms</command>:
<variablelist>
<varlistentry><term>-c</term>
<listitem><para>This option commits changes to disk
only when EVMS CLI exits, not after
each command. </para></listitem></varlistentry>
<varlistentry><term>-f <replaceable>filename</replaceable></term>
<listitem><para>This option tells the EVMS CLI to use
<replaceable>filename</replaceable> as the source of
commands. The EVMS CLI will exit, when it reaches the
end of
<replaceable>filename</replaceable>.
</para></listitem></varlistentry>
<varlistentry><term>-p</term>
<listitem><para>This option parses commands only,
which means that the commands are not actually
executed. When combined with the -f option, the -p option
can be used to catch syntax errors in command files. </para></listitem></varlistentry>
<varlistentry><term>-h</term>
<listitem><para>This option displays help information
for options used with the <command>evms</command>
command.</para></listitem> </varlistentry>
<varlistentry><term>-rl</term>
<listitem><para>This option tells the CLI that all remaining items on the
command line are replacement parameters for use with
EVMS commands. </para>
<note><title>NOTE</title>
<para>Replacement parameters are accessed in EVMS commands using the
<option>$(x)</option> notation, where <replaceable>x</replaceable> is the number identifying which
replacement parameter to use. Replacement parameters are assigned
numbers (starting with 1) as they are encountered on the command line.
Substitutions are not made within comments or quoted strings. </para>
<para>An example would be :
<programlisting>evms -c -f testcase -rl sda sdb</programlisting>
where <option>sda</option> is the replacement for <replaceable>parameter1</replaceable> and
<option>sdb</option> is the replacement for <replaceable>parameter2</replaceable></para></note>
</listitem></varlistentry>
</variablelist></para>
<note><title>NOTE</title>
<para>Information on less commonly used options is available in the EVMS man
page. </para></note>
<para>When the EVMS CLI has been invoked, it processes
the commands or command file you provide. </para>
</sect2>
<sect2 id="NOTECOMMAND"><title>Notes on Commands and Command Files</title>
<para>The EVMS CLI allows multiple commands to appear
on a command line. When using multiple commands on a
single command line, the commands must be separated by
a colon ( : ) . This is
important for command files because the EVMS CLI sees
a command file as a single long command line. The
EVMS CLI has no concept of lines in the file and
ignores spaces. These features allow a command in
a command file to span several lines and use whatever
indentation, or margins that are convenient. The only
requirement is that the command separator (the colon) appear
between commands.</para>
<para>The EVMS CLI ignores spaces unless the spaces
appear within quote marks. Any name that contains
spaces or other non-printable or control characters
should be placed in quotation marks. If the name
contains a quotation mark as part of the name, the
quotation mark must be "doubled" as in the following example:</para>
<programlisting>"This is a name containing ""embedded"" quote marks."</programlisting>
<para>EVMS CLI keywords are not case sensitive, but EVMS
names are case sensitive. Sizes can be input in any units with a unit label, such as KB, MB, GB, or TB.</para>
<para>Finally, C programming language style comments
are supported by the EVMS CLI. Comments can begin and
end anywhere except within a quoted string, as in the
following example:</para>
<programlisting>/* This is a comment */
Create:Vo/*This is a silly place for a comment, but it is
allowed.*/lume,"lvm/Sample Container/My LVM
Volume",compatibility</programlisting>
</sect2>
</sect1>
<!-- LVM Utilities -->
<sect1 id="lvm"><title>Linux LVM IEmulation Tools</title>
<para>You can administer
Linux LVM volumes through a set of command line utilities that emulate the Linux LVM
command set, using the EVMS Engine APIs.</para>
<para>The Linux LVM is based on the concept of volume groups. A volume group (VG) is
a collection of physical volumes (PVs). All PVs in one group have their storage
space subdivided into small, fixed-sized sections called physical extents (PEs).
The default size for a PE is 4 MB. Logical volumes (LVs) are created by
allocating one or more PEs to the new LV. When I/O requests come in for a
volume, the LVM code determines which PV and which PE the request lies
on, and passes the request down the stack to the appropriate device.</para>
<para>As noted in <xref linkend="terminology"/>, EVMS uses different terms than those used
in Linux LVM. However, the two sets of terms are comparable. Volume groups (VGs)
from Linux LVM are called containers in EVMS. Because the LVM plug-in is an EVMS
Region Manager, its output objects (LVs in LVM) are called regions. The input
objects (PVs in LVM) are called segments, even though region
managers can actually take disks and other regions as inputs as well. These
command line utilities will often use the Linux LVM and EVMS terminology interchangeably.</para>
<para>The options for the EVMS emulation of the Linux LVM command set are the same as the
options for the Linux LVM commands. However, some options now have slightly
different meanings. For instance, the verbose option (-v) displays additional
information about the command to the user, but also opens the Engine with DEBUG
level messaging, so that additional information is written to the Engine log
(<filename>/var/log/evmsEngine.log</filename>). The debug option (-d) displays the
same amount of info to the user as the verbose option, but opens the Engine with
ENTRY_EXIT level messaging, which causes detailed trace information to be
written to the Engine log. Also, some options are currently silently ignored,
because their functionality has not been implemented yet, or because that
functionality is not necessary in EVMS. For instance, the auto-backup option (<option>-A</option>)
is ignored because the LVM plug-in
does not yet make metadata backups.</para>
<para>The following commands are available
in the command line utilities. The
options are generally identical to those available from
the Linux LVM commands. Use the <option>--help</option> option for each
command to learn more about that command.</para>
<glosslist>
<glossentry><glossterm><command>evms_vgcreate</command></glossterm>
<glossdef><para>Creates a new LVM volume group
with the given list of PVs. VG commands no longer require the user to prepare objects
with <command>evms_pvcreate</command>. Any available object in EVMS can now
be used directly by these commands. Similarly, the
<command>evms_pvremove</command> command is no longer necessary to release
PVs back to available EVMS
objects.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_vgremove</command></glossterm>
<glossdef><para>Deletes an existing volume
group.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_vgextend</command></glossterm>
<glossdef><para>Adds new PVs to an existing
volume group.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_vgreduce</command></glossterm>
<glossdef><para>Takes PVs out of an existing
volume group.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_vgscan</command></glossterm>
<glossdef><para>Lists all current LVM
VGs. This command also contains a new option
(-c) to force a commit, and the creation of
all necessary device files in
<filename>/dev</filename>. This creation of
files is necessary for existing LVM setups
that have not created any new LVs using the
EVMS tools (unless devfs is enabled). The same
results can also be accomplished by by saving in any of the EVMS interfaces.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_vgdisplay</command></glossterm>
<glossdef><para>Displays extra information
about the specified VG.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_lvcreate</command></glossterm>
<glossdef><para>Creates a new LVM logical
volume. <command>evms_lvcreate</command> supports creating normal (linear) LVs as
well as striped LVs. Linear LVs can be specified as being contiguous. The LVM
plug-in defines contiguous to mean the LV must reside on a
single PV in a contiguous run of PEs. </para>
</glossdef></glossentry>
<glossentry><glossterm><command>evms_lvremove</command></glossterm>
<glossdef><para>Deletes an LVM logical
volume. </para></glossdef></glossentry>
<glossentry><glossterm><command>evms_lvextend</command></glossterm>
<glossdef><para>Expands an existing LV by
adding extents. You must expand the file system
after expanding the LV. This command currently
does not support expanding snapshots or
snapshot originals. The Engine will coordinate the expanding and shrinking of the file system
if the FSIM (file system interface module) for the file system is installed.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_lvreduce</command></glossterm>
<glossdef><para>Shrinks an existing LV by
removing extents. You must shrink the file
system before shrinking the LV. Do not shrink
the LV first, or you will risk losing data
from the file system. This command does not currently
support shrinking snapshots or snapshot
originals. The Engine will coordinate the expanding and shrinking of the file system
if the FSIM (file system interface module) for the file system is installed.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_lvscan</command></glossterm>
<glossdef><para>Lists all current LVM
LVs. When an LV is listed as inactive that LV does not appear as a
compatibility volume in EVMS, and it is not
available for use through EVMS. The
only way this can occur is if the LV was
created in the EVMS GUI and a compatibility
volume was not added. Use
the GUI to perform the task of adding a
compatibility volume to an inactive LV. </para></glossdef></glossentry>
<glossentry><glossterm><command>evms_lvdisplay</command></glossterm>
<glossdef><para>Displays extra information
about the specified LV.</para></glossdef></glossentry>
<glossentry><glossterm><command>evms_pvscan</command></glossterm>
<glossdef><para>Lists all current LVM
PVs. This command also lists all other EVMS
disks, segments, and regions, and marks each
as "available" or "unavailable." Available
objects can be used directly to create or
extend volume groups. </para></glossdef></glossentry>
<glossentry><glossterm><command>evms_pvdisplay</command></glossterm>
<glossdef><para>Displays extra information about the
specified PV.</para></glossdef></glossentry>
</glosslist>
<para>Two commands have been removed from the set of LVM utilities.
<command>evms_pvcreate</command> and
<command>evms_pvremove</command> are no longer
necessary. The <command>evms_pvscan</command> command
will now display all LVM PVs as well as all other
disks, segments, and regions in EVMS, and label them
as available or unavailable. Objects that are marked as
available can be used by <command>evms_vgcreate</command>
without needing to call <command>evms_pvcreate</command>.</para>
</sect1>
</chapter>

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<chapter id="evmsconvert"><title>Converting Volumes</title>
<para> This chapter discusses converting compatibility volumes to EVMS
volumes and converting EVMS volumes to compatibility volumes. For a discussion
of the difference between compatibility and EVMS volumes see <xref linkend="evmscreatevol"/>.</para>
<sect1><title>When to Convert Volumes</title>
<para>There are a several different scenarios that might help you determine what type of volumes you need. For example, if you wanted persistent names or to make full use of EVMS features, such as BBR, Drive Linking, or Snapshotting, you would convert your compatibility volumes to EVMS volumes. In another situation, you might decide that a volume needs to be read by a system that understands the underlying volume management scheme. In this case you would convert your EVMS volume to a compatibility volume.</para>
</sect1>
<sect1 id="comptoevms"><title>Working through an Example of Converting Compatibility Volumes to EVMS Volumes</title>
<para>A compatibility volume
can be converted to an EVMS volume in the following situations:
<itemizedlist><listitem><para>The compatibility volume has no filesystem (FSIM) on it.</para></listitem>
<listitem><para>The compatibility volume has a filesystem, but the filesystem has been shrunk (if necessary) to make
room for the EMVS metadata.</para></listitem></itemizedlist></para>
<para>This section provides a detailed explanation of how to convert compatibility
volumes to EVMS volumes by providing instructions to help you complete the following task. </para>
<blockquote><example><title>Convert a compatibility volume</title>
<para>You have a compatability volume <filename>/dev/evms/hda3</filename>
that you want to make an EVMS volume named <filename>my_vol</filename>.</para></example></blockquote>
<sect2 id="c2egui"><title>Using the EVMS GUI</title>
<orderedlist>
<listitem><para>Choose <menuchoice><guimenu>Action</guimenu>
<guimenuitem>Convert </guimenuitem>
<guimenuitem>Compatibility Volume to EVMS</guimenuitem>
</menuchoice>. </para></listitem>
<listitem><para>Select <filename>/dev/evms/hda3</filename>
from the list of available volumes.</para></listitem>
<listitem><para>Type <filename>my_vol</filename> in the name field.</para></listitem>
<listitem><para>Click the <guibutton>Convert</guibutton> button
to convert the volume.</para></listitem>
</orderedlist>
</sect2>
<sect2 id="c2encur"><title>Using Ncurses</title>
<orderedlist>
<listitem><para>Press the <keycap>2</keycap> key to see the volume view.</para></listitem>
<listitem><para>Highlight <filename>/dev/evms/hda3</filename> by
using the up and down arrow keys to scroll through the volumes.Press the
<keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <guimenuitem>Convert to EVMS Volume</guimenuitem>. Press the
<keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Type <userinput>my_vol</userinput> at the "::" prompt.
Press the <keycap>Enter</keycap> key.</para></listitem>
</orderedlist>
</sect2>
<sect2><title>Using the CLI</title>
<para>To convert a volume use the <command>Convert</command> command.
The <command>Convert</command> command takes the name of a volume as its first argument, and
then <option>name=</option> for what you want to name the new volume
as the second argument. To complete the example and convert a volume, type the
following command at the <prompt>EVMS:</prompt> prompt:</para>
<programlisting>convert: /dev/evms/hda3, Name=my_vol</programlisting>
</sect2>
</sect1>
<sect1 id="evmstocomp"><title>Working through an Example of Converting EVMS Volumes to Compatibility Volumes</title>
<para>An EVMS volume can be converted to a compatibility volume only if the volume does not have EVMS
features on it. This section provides a detailed explanation of how to convert EVMS volumes to compatibility volumes
by providing instructions to help you complete the following task. </para>
<blockquote><example><title>Convert an EVMS Volume</title>
<para>You have an EVMS volume, <filename>/dev/evms/my_vol</filename>
that you want to make a compatibility volume.</para></example></blockquote>
<sect2 id="e2cgui"><title>Using the EVMS GUI</title>
<orderedlist>
<listitem><para>Choose <menuchoice><guimenu>Action</guimenu>
<guimenuitem>Convert </guimenuitem>
<guimenuitem>EVMS Volume to Compatibility Volume</guimenuitem>
</menuchoice>. </para></listitem>
<listitem><para>Select <filename>/dev/evms/my_vol</filename>
from the list of available volumes.</para></listitem>
<listitem><para>Click the <guibutton>Convert</guibutton> button
to convert the volume.</para></listitem>
</orderedlist>
</sect2>
<sect2 id="e2cncur"><title>Using Ncurses</title>
<orderedlist>
<listitem><para>Press the <keycap>2</keycap> key to see the volume view.</para></listitem>
<listitem><para>Highlight <filename>/dev/evms/my_vol</filename>.
Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <menuchoice><guimenuitem>Convert to Compatibility Volume</guimenuitem>
</menuchoice>. Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Highlight <menuchoice><guimenuitem>Convert</guimenuitem></menuchoice> to confirm.
Press the <keycap>Enter</keycap> key.</para></listitem>
</orderedlist></sect2>
<sect2 id="e2ccli"><title>Using the CLI</title>
<para>To convert a volume use the <command>Convert</command> command.
The <command>Convert</command> command takes the name of a volume as its first argument, and
the keyword <option>compatibility</option> to indicate a change to a compatibility volume
as the second argument. To complete the example and convert a volume, type the
following command at the <prompt>EVMS:</prompt> prompt:</para>
<programlisting>convert: /dev/evms/my_vol, compatibility</programlisting></sect2>
</sect1>
</chapter>

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<chapter id="evmscreatecont"><title>Creating a Container </title>
<para>The following chapter discusses when and how to create a container. </para>
<sect1 id="whencont"><title>When to Create a Container</title>
<para>Segments and disks may be combined to form a container. Containers allow you to combine
storage objects and then subdivide those combined storage objects into new storage objects. You can
combine storage objects to implement the volume group concept
as found in the AIX and Linux logical volume managers.</para>
<para>Containers are the beginning of more flexible
volume management. You might want to create a container in order to account for flexibility in your future storage needs. For example, you might
need to add additional disks when your applications or users need more storage. </para>
</sect1>
<sect1 id="contex"><title>Working through an Example</title>
<para>This section provides a detailed explanation of how to create a container with EVMS by providing instructions
to help you complete the following task.</para>
<blockquote><example><title>Create &quot;Sample Container&quot;</title>
<para>Given a system with three available disk drives (sdc, sdd, hdc), use the EVMS LVM Region Manager to
combine these disk drives into a container called "Sample Container" with a PE size of 16 MB. </para></example></blockquote>
<sect2 id="guicont"><title>Using the EVMS GUI</title>
<para>To create a container using the EVMS GUI, follow the steps below:
<orderedlist>
<listitem><para>Select
<menuchoice>
<guimenu>Actions</guimenu>
<guimenuitem>Create</guimenuitem>
<guimenuitem>Container</guimenuitem></menuchoice>
to see a list plug-ins that support container creation.</para></listitem>
<listitem><para>Select the
<guimenu>LVM Region Manager</guimenu>. Click
<guibutton>Next</guibutton>.</para>
<para>The next dialog window contains a list of storage objects
that the LVM Region Manager can use to create a container. </para></listitem>
<listitem><para>Select <guilabel>sdc</guilabel>, <guilabel>sdd</guilabel>, and
<guilabel>hdc</guilabel> from the list. Click
<guibutton>Next</guibutton> </para></listitem>
<listitem><para>Enter the name <userinput>Sample Container</userinput>
for the container and <userinput>16MB</userinput> in the
<guilabel>PE size</guilabel> field.</para></listitem>
<listitem><para>Click the
<guibutton>Create</guibutton>
button. A window that displays the
outcome appears.</para>
</listitem>
</orderedlist>
</para>
</sect2>
<!--ncurses-->
<sect2 id="ncurcont"><title>Using Ncurses</title>
<para>To create a container using the Ncurses interface, follow the steps below:
<orderedlist>
<listitem><para>Press the
<keycap>4</keycap> key to switch
views.</para> </listitem>
<listitem><para>Scroll down the list
using the down arrow key to the
<guimenuitem>Storage
Containers</guimenuitem>. Press the
<keycap>Enter</keycap> key.</para> </listitem>
<listitem><para>Press the <keycap>Enter</keycap> key again to
display a sub menu.</para> </listitem>
<listitem><para>Scroll down until you highlight <guimenuitem>Create a New Container</guimenuitem>.
Press the <keycap>Enter</keycap> key. You should see a list of plug-ins that support container
creation.</para> </listitem>
<listitem><para>Select
<guimenuitem>LVM Region Manager</guimenuitem>. Press the
<keycap>Enter</keycap> key.</para>
<para>The next sub menu contains a
list of storage objects, such as
segments, disks, or regions the
LVM Region Manager finds acceptable to
use for the creation of a
container.</para> </listitem>
<listitem><para>Use the
<keycap>spacebar</keycap> to select <guilabel>sdc</guilabel>,
<guilabel>sdd</guilabel>, and <guilabel>hdc</guilabel> from
the list. Press the <keycap>Enter</keycap> key. Selected disks will be marked with
an <guilabel>x</guilabel>.</para> </listitem>
<listitem><para>Press the
<keycap>spacebar</keycap> key to
select the field for the container
name.</para> </listitem>
<listitem><para>Type <userinput>Sample Container</userinput> at the "::" prompt. Press the
<keycap>Enter</keycap> key.</para> </listitem>
<listitem><para>Scroll down until <guilabel>PE Size</guilabel> is highlighted. Press the <keycap>spacebar</keycap>.</para></listitem>
<listitem><para>Scroll down until <guilabel>32768</guilabel> is highlighted. Press the <keycap>spacebar</keycap>.
<note><title>NOTE</title>
<para>In Ncurses PE Size is listed in sectors, so 16MB = 32768 (512B) sectors.</para></note></para></listitem>
<listitem><para>Press the <keycap>Enter</keycap> key to complete
the operation.</para></listitem>
</orderedlist>
</para>
</sect2>
<!--CLI-->
<sect2 id="clicont"><title>Using the CLI</title>
<para>The <command>Create</command> command is
used to create containers. The first argument
in the <command>Create</command> command is the type of object to
produce, in this case a container. The
<command>Create</command> command then accepts
the following arguments: the region manager to
use along with any parameters it might need, and
the segments or disks to create the container
from. The command to complete the example
above is:</para>
<programlisting>
Create:Container,LvmRegMgr={name="Sample Container",pe_size=16KB},sdc,sdd,hdc
</programlisting>
<para>The example above accepts the default values for all options you don't specify. To see the options for this command type:
<programlisting>query:plugins,plugin=LvmRegMgr,list options</programlisting></para>
</sect2>
<sect2><title>Using Linux LVM Emulation Tools </title>
<para>To create a container using the Linux LVM emulation tools, type the following at the command prompt: </para>
<programlisting>evms_vgcreate --verbose --physicalextentsize 16MB &quot;Sample Container&quot; sdc sdd hdc</programlisting>
<para>For a listing of other options used with the <command>evms_vgcreate</command> command type:</para>
<programlisting>evms_vgcreate -h</programlisting>
</sect2>
</sect1>
</chapter>

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<chapter id="evmscreatereg"><title>Creating Regions</title>
<para>Regions can be created from containers, but they can also be created from other
regions, segments, or disks. Most region managers that support containers will create one or more
freespace regions to represent the freespace within the container. This function is
analogous to the way a segment manager creates a freespace segment to represent unused disk
space. </para>
<sect1><title>When to Create Regions</title>
<para>You can create regions because you want the features provided by a certain region manager.
or because you want the features provided by that region manager.You can also create regions to be compatible with other volume management technologies, such as MD or
LVM. For example,
if you wanted to make a volume that is compatible with Linux LVM, you would create a
region out of a Linux LVM container and then a comptibility volume from that region. </para>
</sect1>
<sect1 id="crregex"><title>Working through an Example</title>
<para>This section provides a detailed explanation of how to create a region with EVMS by
providing instructions to help you complete the following task.</para>
<blockquote><example><title>Create &quot;Sample Region&quot;</title>
<para>Given the container "Sample Container," which has a freespace region of 8799 MB
create a data region 1000 MB in size named "Sample Region."</para></example></blockquote>
<sect2 id="guireg"><title>Using the EVMS GUI</title>
<para>To create a region, follow the steps below:
<orderedlist><listitem><para>Select
<menuchoice>
<guimenu>Actions</guimenu>
<guimenuitem>Create</guimenuitem>
<guimenuitem>Region</guimenuitem></menuchoice>
to see a list of region
manager plug-ins. </para></listitem>
<listitem><para>Select
the <guisubmenu>LVM Region
Manager</guisubmenu>. Click <guibutton>Next</guibutton>.</para>
<note><title>NOTE</title>
<para>You may
see additional region managers that were
not in the selection list when you were creating the storage container
because not all region
managers are required to support containers.</para></note></listitem>
<listitem><para>Select the freespace region from
the container you created in <xref linkend="evmscreatecont"/>.
The region should be named
<filename>lvm&sol;Sample Container&sol;Freespace</filename>.
Click <guibutton>Next</guibutton>.</para>
<para>The fields in the next window are the options for the
LVM Region Manager plug-in,the options marked with an "*" are required. </para></listitem>
<listitem><para>Fill in the name,<userinput>Sample Region</userinput>.</para></listitem>
<listitem><para>Enter <userinput>1000MB</userinput> in the <guilabel>size</guilabel> field.</para></listitem>
<listitem><para>Click the
<guibutton>Create</guibutton> button to complete the
operation. A window that displays the
outcome appears. </para>
</listitem>
</orderedlist>
</para>
</sect2>
<!--ncurses-->
<sect2 id="ncurreg"><title>Using Ncurses</title>
<para>To create a region, follow the steps below:
<orderedlist>
<listitem><para>Press the
<keycap>4</keycap> key to switch
views.</para> </listitem>
<listitem><para>Scroll down the
list using the <keycap>down</keycap> arrow key until
<guimenuitem>Storage
Regions</guimenuitem> is
highlighted. Press the
<keycap>Enter</keycap> key.</para> </listitem>
<listitem><para>Press the
<keycap>Enter</keycap> key again to
display a submenu. </para></listitem>
<listitem><para>Press the
<keycap>Enter</keycap> key when
<guimenuitem>Create a New
Region</guimenuitem> is
highlighted. You will be presented
with a list of region manager
plug-ins.</para></listitem>
<listitem><para>Select the
<guimenuitem>LVM Region
Manager</guimenuitem>. Press the <keycap>Enter</keycap> key.</para>
<note><title>NOTE</title>
<para>You might see additional region
managers that were not in the
selection list when you created
the storage container. This absence of
region managers occurs
because not all region managers are
required to support
containers.</para></note></listitem>
<listitem><para>Select the freespace
region from the container you created
earlier in <xref linkend="evmscreatecont"/>. The region should be
named
<filename>lvm&sol;Sample Container&sol;Freespace</filename>.</para></listitem>
<listitem><para>Use the <keycap>spacebar</keycap>
key to select it. Press the
<keycap>Enter</keycap> key to
continue. The configuration options
submenu should
appear. </para></listitem>
<listitem><para>Scroll to the <guilabel>Name</guilabel> field, and press
<keycap>spacebar</keycap></para></listitem>
<listitem><para>Type <userinput>Sample Region</userinput> at the "::" prompt.
Press <keycap>Enter</keycap>.</para></listitem>
<listitem><para>Scroll to the <guilabel>size</guilabel> field, and press
the <keycap>spacebar</keycap></para></listitem>
<listitem><para>Type <userinput>1000</userinput> at the "::" prompt.
Press <keycap>Enter</keycap>.</para></listitem>
<listitem><para>Check all fields to make sure they were entered appropriately.
If the units are displayed as KB and you desired MB, return to the previous step,
and enter the value of KB that is equal to the MB value you desired.</para></listitem>
</orderedlist>
</para>
</sect2>
<!--CLI-->
<sect2 id="clireg"><title>Using the CLI</title>
<para>Regions are created using the <command>Create</command>
command. Arguments to the <command>Create </command>command are
the following: keyword Region, the name of the
region manager to use, the region managers
options, and the objects to consume. The form of this command is:</para>
<programlisting>Create:region, LvmRegMgr={name="Sample Region"; size=1000MB},"lvm/Sample Container/freespace"</programlisting>
<para>The LVM Region Manager supports many
options for creating regions. To see the
available options for creating regions and
containers, use the <command>Query</command> command as follows: </para>
<programlisting>query:plugins,plugin=LvmRegMgr,list options</programlisting>
</sect2>
<sect2 id="lvmreg"><title>Using Linux LVM Emulation Tools </title>
<para>The command that creates a region in LVM also creates an EVMS compatibility volume. Details on creating regions with the Linux LVM emulation tools can be found in the <xref linkend="lvmcomp"/>.</para></sect2>
</sect1>
</chapter>

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<chapter id="evmscreateseg"><title>Creating Segments</title>
<para>The following chapter discusses when to use segments and how to create segments using
different EVMS interfaces.</para>
<sect1 id="whyseg"><title>When to Create a Segment</title>
<para>A disk can be subdivided into smaller storage objects called disk segments. A segment manager plug-in provides this capability. Another reason for creating disk segments is to maintain compatibility on a dual boot system where the other operating system requires disk partitions. Before creating a disk segment, you must choose a segment manager plug-in to manage the disk and assign
the segment manager to the disk. An explanation of when and how to assign segment managers can be found in <xref linkend="evmsassignseg"/>.</para>
</sect1>
<sect1 id="crsegex"><title>Working through an Example</title>
<para> This section provides a detailed explanation of how to create a
segment with EVMS by providing instructions to help you complete the following task:</para>
<blockquote><example><title>Create a 100MB egment</title>
<para>Create a 100MB segment from the freespace segment sde_freespace1. This
freespace segment lies on a drive controlled by the DOS Segment Manager. </para></example></blockquote>
<sect2 id="guiseg"><title>Using the EVMS GUI</title>
<para>To create a segment using the GUI, follow the steps below:
<orderedlist>
<listitem><para>Select
<menuchoice>
<guimenu>Actions</guimenu>
<guimenuitem>Create</guimenuitem>
<guimenuitem>Segment</guimenuitem>
</menuchoice>
to see a list of segment manager plug-ins.
</para></listitem>
<listitem><para>Select
<guimenuitem>DOS Segment Manager</guimenuitem>.
Click <guibutton>Next</guibutton>.</para>
<para>The next dialog window lists
the free space storage objects suitable for creating
a new segment.</para></listitem>
<listitem><para>Select <filename>sde_freespace1</filename>. Click
<guibutton>Next</guibutton>. </para>
<para>The last dialog window
presents the free space object you
selected as well as the available
configuration options for that
object.</para></listitem>
<listitem><para>Enter 100 MB. Required fields are denoted by the
"*" in front of the field description. The DOS Segment
Manager provides default values, but you might want to change
some of these values.</para>
<para>After you have filled in
information for all the required
fields, the <guibutton>Create</guibutton>
button becomes available.</para></listitem>
<listitem><para>Click the
<guibutton>Create</guibutton>
button. A window that displays the
outcome appears. </para>
</listitem>
</orderedlist></para>
</sect2>
<!-- Ncurses-->
<sect2 id="ncurseg"><title>Using Ncurses</title>
<para>To create a segment using the Ncurses, follow the steps below:</para>
<orderedlist>
<listitem><para>Press the <keycap>4</keycap> key
to switch views.</para></listitem>
<listitem><para>Scroll down using the
down arrow key until <guimenuitem>Disk Segments</guimenuitem> is highlighted.
Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Press the <keycap>Enter</keycap> key
again to display a sub menu on the
current selection.</para></listitem>
<listitem><para>Select <guimenuitem>Create a
New Segment</guimenuitem>. Press the
<keycap>Enter</keycap> key. You should see a list of segment
manager plug-ins. </para></listitem>
<listitem><para>Select <guimenuitem>DOS Segment Manager</guimenuitem>. Press the <keycap>Enter</keycap>
key.</para>
<para>The next dialog window
will present a list of free space
storage objects suitable for creating
a new segment. </para></listitem>
<listitem><para>Select <filename>sde_freespace1</filename> by moving to it with the arrow
keys and then using the <keycap>spacebar</keycap> key
to select it. After the storage object is selected (it
is marked by an &quot;X&quot;), press the <keycap>Enter</keycap> key.</para>
<para>The last dialog window displays the selected freespace object and configuration options
available from the plug-in manager. Required fields are denoted by the "*" in front of the field
description. The DOS Segment Manager provides default values, but you might want to change some of these
values. </para></listitem>
<listitem><para>Highlight the <guilabel>size field</guilabel> and press the <keycap>spacebar</keycap> key.</para></listitem>
<listitem><para>At the &quot;::&quot; prompt enter <userinput>100</userinput>.
Press the <keycap>Enter</keycap> key. </para> </listitem>
<listitem><para>Check all fields to make sure they were entered appropriately. If the units are displayed as KB, and you desired MB, return to step 7 and enter the value of KB that is equal to the MB value you desired. For example, instead of entering 100 you would enter 102400 (100 x 1024) to convert the KB value to MB. </para></listitem>
<listitem><para>Once all required values have been completed, press the <keycap>Enter</keycap> key
and a results status message will be displayed. </para> </listitem>
</orderedlist>
</sect2>
<!-- CLI-->
<sect2 id="cliseg"><title>Using the CLI</title>
<para>To create a data segment from a
freespace segment, use the
<command>Create</command> command. The arguments the
<command>Create</command> command accepts vary
depending on what is being created. The first
argument to the <command>Create</command>
command indicates what is to be created, which
in the above example is a segment. The
remaining arguments are the freespace segment
to allocate from and a list of options to pass
to the segment manager. The command to
accomplish this is:</para>
<programlisting>Create: Segment,sde_freespace1, size=100MB</programlisting>
<note><title>NOTE</title>
<para>The <command>Allocate</command> command will also work to create a segment. </para></note>
<para>The example above accepts the default values for all options you don't specify. To see the options for this command type:<programlisting>query:plugins,plugin=DosSegMgr,list options</programlisting></para>
</sect2>
</sect1>
</chapter>

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<?xml version="1.0" encoding="iso-8859-1"?>
<chapter id="evmscreatesobj"><title>Creating Storage Objects</title>
<para>Storage objects are created from
segments, regions, disks, or other storage
objects. Storage objects are typically
used when an EVMS specific feature is desired
on a volume, such as Bad Block Relocation
(BBR). </para>
<sect1 id="EVMSCRSO"><title>Using CLI</title>
<para>Storage objects are created using the
<command>Create</command> command. In this
case, the arguments to the
<command>Create</command> command are the
keyword <command>Object</command> followed by the name of the EVMS feature to
use along with its options, and the segments,
disks, regions, and storage objects to use to
create the new storage object.</para>
<note><title>Example</title>
<para>Given the region <filename>lvm/Sample
Container/Sample Region</filename>, create a
storage object called BBR_Region using the
EVMS Bad Block Relocation
feature.</para></note>
<para>Because the BBR feature supports only
one option, <option>name</option>, the command
to complete this example is:</para>
<programlisting>Create:Object,BBR={name=BBR_Region},"lvm/Sample Container/Sample Region"</programlisting>
<note><title>NOTE</title>
<para>The EVMS CLI ignores spaces. Any name
containing spaces must appear in quotation
marks.</para></note>
</sect1>
</chapter>

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<chapter id="evmscreatevol"><title>Creating Volumes</title>
<para>This following chapter discusses when and how to create volumes.</para>
<sect1><title>When to Create a Volume</title>
<para>EVMS treats volumes and storage objects as separate. A storage object does not automatically
become a volume. Instead, a storage object must be made into a volume.</para>
<para>Volumes are created from storage objects.
Volumes are either EVMS native volumes or compatibility volumes. Compatibility volumes
are intended to be compatible with a volume manager other than EVMS, such as the Linux
LVM, MD, OS/2 or AIX. Compatibility volumes might have restrictions on what EVMS can do with
them. EVMS native volumes have no such restrictions, but they can only be used by an
EVMS equipped system. Volumes are mountable and can contain filesystems.</para>
<para>EVMS native volumes contain EVMS-specific information
to identify the name and minor number. After this volume information is
applied, the volume is no longer fully backwards compatible
with existing volume types.</para>
<para>Instead of
adding EVMS metadata to an existing object, we can tell EVMS to make an object directly available as a volume. This type of
volume is known as a compatibility volume. Using this method, the final product is fully
backwards-compatible with the desired system. </para>
</sect1>
<sect1 id="crvolexcomp"><title>Working through an Example of Creating an EVMS Native Volume</title>
<para>This section provides a detailed explanation of how to create an EVMS native
volume with EVMS by providing instructions to help you complete the following task.</para>
<blockquote><example><title>Create an EVMS native volume </title>
<para>Create an EVMS native volume called &quot;Sample Volume&quot; from the region, <filename>/lvm/Sample Container/Region</filename>, you created in <xref linkend="evmscreatereg"/>.</para></example></blockquote>
<sect2 id="evmsguivol"><title>Using the EVMS GUI</title>
<para>Follow the instructions below to create an EVMS volume:</para>
<orderedlist><listitem><para>Select <menuchoice><guimenu>Actions</guimenu>
<guimenuitem>Create</guimenuitem>
<guimenuitem>EVMS Volume</guimenuitem></menuchoice></para></listitem>
<listitem><para>Choose <filename>lvm/Sample Container/Sample Region</filename>.
</para></listitem>
<listitem><para>Type <userinput>Sample Volume</userinput> in the
<guilabel>name field</guilabel>.</para></listitem>
<listitem><para>Click <guibutton>Create</guibutton></para></listitem></orderedlist>
</sect2>
<sect2 id="ncurevmsvol"><title>Using Ncurses</title>
<para>To create a volume, follow the steps below:
<orderedlist>
<listitem><para>Press the <keycap>4</keycap> key to switch views.</para></listitem>
<listitem><para>Scroll down the list using the <keycap>down</keycap> arrow key to the
available topmost storage object. Press the <keycap>Enter</keycap> key</para></listitem>
<listitem><para>Highlight <filename>lvm/Sample Container/Storage Region</filename>.
Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Select <guimenuitem>Create EVMS Volume from
the Storage Object</guimenuitem>. Press the
<keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Confirm the creation
of the volume.</para> </listitem>
<listitem><para>Enter <userinput>Sample Volume</userinput> at the "::" prompt.
Press the
<keycap>Enter</keycap> key to complete
the operation.</para> </listitem></orderedlist>
</para>
<para>If you look at the volumes view
(<keycap>2</keycap>), you should see your new volume.</para>
</sect2>
<sect2><title>Using the CLI</title>
<para>To create a volume, use the <command>Create</command> command. The arguments
the <command>Create</command> command accepts vary depending on what is being created. In
the case of the example, the first argument is the key word <option>volume</option> that
specifies what is being created. The second argument is the object being made into a volume,
in this case <option>lvm/Sample Container/Sample Region</option>.
The third argument is type specific for an EVMS volume we need <option>Name=</option> and what
you want to call the volume, in this case <option>Sample Volume</option>. The following command
creates the volume from the example. </para>
<programlisting>Create: Volume, &quot;lvm/Sample Container/Sample Region&quot;, Name="Sample Volume"</programlisting>
</sect2>
</sect1>
<sect1 id="crvolexevms"><title>Working through an Example of Creating a Compatibility Volume</title>
<para>This section provides a detailed explanation of how to create a compatibility
volume with EVMS by providing instructions to help you complete the followint task.</para>
<blockquote><example><title>Create a compatibility volume</title>
<para>Create a compatibility volume called &quot;Sample Volume&quot; from
the region, <filename>/lvm/Sample Container/Region</filename>, you created in <xref linkend="evmscreatereg"/>.</para></example></blockquote>
<sect2 id="guicompvol"><title>Using the GUI</title>
<para>To create a compatibility volume, follow the steps below:</para>
<orderedlist>
<listitem><para>Select
<menuchoice><guimenu>Actions</guimenu>
<guimenuitem>Create</guimenuitem>
<guimenuitem>Compatibility Volume</guimenuitem></menuchoice>.
</para></listitem>
<listitem><para>Choose the region <filename>lvm/Sample Container/Sample Region</filename>
from the list</para></listitem>
<listitem><para>Click the <guibutton>Create</guibutton> button.</para></listitem>
<listitem><para>Click on the <guilabel>Volume</guilabel> tab in the GUI to
see a volume named <filename>/dev/evms/lvm/Sample Container/Sample Region</filename>.
This volume is your compatibility volume.</para></listitem>
</orderedlist>
</sect2>
<sect2 id="ncurcompatvol"><title>Using Ncurses</title>
<para>To create a compatibility volume, follow the steps below:</para>
<orderedlist>
<listitem><para>Press the <keycap>4</keycap> key to switch views.</para></listitem>
<listitem><para>Scroll down the list using the <keycap>down</keycap> arrow key to the
available topmost storage object. Press the <keycap>Enter</keycap> key</para></listitem>
<listitem><para>Highlight <filename>lvm/Sample Container/Storage Region</filename>.
Press the <keycap>Enter</keycap> key.</para></listitem>
<listitem><para>Select <guimenuitem>Create Compatibility Volume from Storage Object</guimenuitem>.
Press the <keycap>Enter</keycap> key. </para></listitem>
<listitem><para>Confirm the creation of the volume.</para> </listitem>
</orderedlist>
</sect2>
<sect2><title>Using the CLI</title>
<para>To create a volume, use the <command>Create</command> command. The arguments
the <command>Create</command> accepts vary depending on what is being created. In
the case of the example, the first argument is the key word <option>volume</option> that
specifies what is being created. The second argument is the object being made into a volume,
in this case <option>lvm/Sample Container/Sample Region</option>.
The third argument, <option>compatibility</option>, indicates that this is a compatibility
volume and should be named as such. </para>
<programlisting>Create:Volume,"lvm/Sample Container/Sample Region",compatibility</programlisting>
</sect2>
<sect2 id="lvmcomp"><title>Using Linux LVM Emulation Tools</title>
<para>Using Linux LVM emulation tools, you can create only an EVMS compatibility volume, not an EVMS native volume. To create a region and a corresponding EVMS compatibility volume, type the following:</para>
<programlisting>evms_lvcreate --verbose --size 1000M --name &quot;Sample Region&quot; &quot;Sample Container&quot;</programlisting>
<para>For help and additional options available with <command>evms_lvcreate</command> type the following:</para>
<programlisting>evms_lvcreate -h</programlisting>
</sect2>
</sect1>
</chapter>

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<chapter id="evmsuginstall"><title>Downloading and Installing EVMS </title>
<para>This chapter helps you make informed decisions about how you want to install and configure your EVMS system. In order to get the best understanding of the different options and steps for installing EVMS, read this chapter in its entirety before you begin the process.</para>
<sect1 id="beforebegin"><title>Preparing Your System</title>
<para>You will need to make several
choices when installing EVMS, such as how you want to build EVMS and which
capabilities you want to enable. You will also need you will need to make sure
that you have a kernel source tree. The following sections explain these choices and
guide you through the installation process.</para>
<sect2 id="selectcapabilities"><title>Choosing Capabilities</title>
<para>EVMS has many capabilities. Certain options you choose during install
allow EVMS to be compatible with logical volumes from Linux
LVM, AIX LVM, and OS/2 LVM, as well as Linux MD/Software
RAID. EVMS also has unique features,
such as bad block relocation. If
you do not know which capabilities you want to use, turn
on kernel support for all the options. You can decide
which ones to use after the Engine and user-space
administration tools are installed.</para>
<sect3 id="mdsjupport"><title>MD Support</title>
<para>If you choose to turn
on EVMS MD support, <emphasis>do not </emphasis>enable native MD support (in the
<guimenuitem>Multi-device Support</guimenuitem> menu). MD
rewrites its metadata from within the kernel, and if both
systems recognize the same volume, it could cause metadata
corruption.</para>
</sect3>
<sect3 id="lvmsupport"><title>EVMS Linux LVM</title>
<para>If you choose to
turn on EVMS Linux LVM support, you can enable native Linux
LVM support. Avoid mounting the same volume through
both systems at the same time, or you could cause volume data
corruption. Also, if you use one system to make a change to
a volume or group configuration, you might need to reboot for
the other system to fully recognize the changes.</para>
</sect3>
</sect2>
<sect2 id="buildingopt"><title>Selecting Building Options</title>
<para>You have the option of building EVMS as kernel
modules instead of compiling EVMS directly into the kernel.
However, if you choose to build EVMS as modules, EVMS will not automatically
perform discovery at kernel boot time. You will need to load the
necessary kernel modules from user-space using <command>insmod
</command> or <command>modprobe</command>. Then, use the
<command>evms_rediscover</command> utility to tell EVMS to
discover the logical volumes. </para>
<para>If you decide to build EVMS as kernel modules, and you
want your root file-system on an EVMS volume, you must use an
init-ramdisk during boot. See <xref linkend="INITRD"/> for instructions on adding
EVMS support to your init-ramdisk .
</para>
<note><title>NOTE</title>
<para>If you choose to build EVMS as
kernel modules, you will need to compile all EVMS plug-ins as
modules. If you compile some plug-ins as modules and some
plug-ins directly into the kernel, the plug-ins that are in the
kernel will perform automatic boot-time discovery, without the
remaining plug-ins being active. This inconsistency could produce
incorrect volumes. It is strongly recommended that you not build EVMS as modules without
adding support to your EVMS ramdisk. EVMS configurations built as modules that do not
have support in the ramdisk do not allow EVMS to offer the usual protections against corrupting
data</para></note>
<para>If you have built the plug-ins as
modules, and do not wish to mount your root
file system
using EVMS, simply add entries in your
<filename>init</filename> scripts to
load all the necessary EVMS modules and run the
<command>evms_rediscover</command>
utility. You should run the rediscover early in
the boot scripts before the <filename>/etc/fstab</filename> file is
processed.</para> </sect2>
<sect2 id="kernelsource"><title>Kernel Source Tree</title>
<para>To install EVMS, you will need to add EVMS support to your Linux
kernel. Currently,
EVMS support is not included in the main Linux kernel.
EVMS patches for the kernel are included in the EVMS package on the
<ulink url="http://www.sourceforge.net/projects/evms/">EVMS project website</ulink>. The current
EVMS package contains a patch against both the 2.4 and
2.5 kernel series.</para>
<note><title>NOTE</title>
<para>EVMS will not work with 2.3, 2.2, or earlier kernel series.
</para></note>
<para>If you do not have a Linux kernel source tree,
you can obtain one from <ulink url="http://www.kernel.org/">The Linux Kernel Archives </ulink>.
The current recommended
kernel to use is 2.4.19, but most 2.4 series kernels will
work. </para>
</sect2>
</sect1>
<sect1 id="DOWNLOADING">
<title>Downloading EVMS</title>
<para>To install EVMS, download the latest version EVMS
(<filename>evms-1.2.0.tar.gz</filename>) from the
<ulink url="http://www.sourceforge.net/projects/evms/">EVMS project homepage</ulink>. This
file contains source code patches for the Linux kernel and
source code for all necessary user-space administration tools.</para>
<para>After downloading the file,
<command>untar</command> it in the appropriate
place, using the following command:</para>
<programlisting>
<![CDATA[
cd /usr/src
tar xvzf evms-1.2.0.tar.gz
]]>
</programlisting>
<note><title>NOTE</title>
<para>The command
above assumes the file will be untarred in
<filename>/usr/src</filename>. You can substitute another directory.</para></note>
</sect1>
<sect1 id="PATCHING">
<title>Patching the Kernel</title>
<para>You must apply three patches to your kernel tree
to include EVMS support:
<itemizedlist>
<listitem><para>a patch specific to
your version of the kernel. </para></listitem>
<listitem><para>a patch that includes
all the EVMS specific source code.</para></listitem>
<listitem><para>a patch that adds
code to allow the filesystems to perform flushing and
locking when certain volume configuration changes take
place. This third patch is necessary only when
you want to take SnapShot volumes of journaling
filesystems, such as JFS, ReiserFS, ext3, and XFS.</para></listitem>
</itemizedlist></para>
<para>To apply the patches to the kernel, complete the following steps:
<orderedlist>
<listitem><para>Determine which kernel version
you are using.</para></listitem>
<listitem><para>Find the appropriate patch in the
<filename>kernel</filename> directory of the EVMS
package. This example will use a system running kernel
2.4.19, and a
kernel source tree in <filename>/usr/src/linux</filename>.
<note><title>NOTE</title>
<para>If your kernel source tree is in a different location,
you will need to make the appropriate changes to these instructions.</para></note>
</para></listitem>
<listitem><para>Apply the first patch to your
kernel tree by typing the following commands:
<programlisting>
<![CDATA[
cd /usr/src/linux
patch -p1 < /usr/src/evms-/kernel/evms-linux-2.4.19-common-files.patch
]]>
</programlisting>
</para></listitem>
<listitem><para>From the same directory as the
previous step, type the following command to
apply the actual EVMS code to any 2.4 kernel tree:
<programlisting>
<![CDATA[
patch -p1 < /usr/src/evms-/kernel/evms-1.2.0-linux-2.4.patch
]]>
</programlisting>
</para>
<para>If you are running a 2.5 kernel, substitute
<filename>evms-1.2.0-linux-2.5.patch</filename>
in the command above.</para>
</listitem>
<listitem><para>To apply the optional VFS Locking Patch, remain in the
<filename>/usr/src/linux</filename> directory, and type the following command:
<programlisting>
<![CDATA[
patch -p1 < /usr/src/evms-1.2.0/kernel/linux-2.4.19-VFS-lock.patch
]]>
</programlisting></para></listitem>
</orderedlist></para>
<para>Distributions make modifications to the Linux kernel
that are sometimes incompatible with the code in EVMS.
If you are patching a kernel from a
distribution, the above commands might produce patch
failures, and you might need to manually patch the
affected files. To make the installation easier, it is
recommended that you start with a clean kernel from
kernel.org.</para>
</sect1>
<sect1 id="configuring">
<title>Configuring the Kernel</title>
<para>After patching the kernel, configure it with EVMS support. To
configure the kernel, complete the following steps:</para>
<orderedlist>
<listitem><para>Type the following command:
<programlisting>make xconfig</programlisting>
<note><title>NOTE</title>
<para>You can also use <command>config</command> or
<command>menuconfig</command> if you don't have an Xwindow system.</para></note></para>
<para>If you are using an Xwindow system, the following window appears. </para>
<figure><title>xconfig Window</title>
<mediaobject><imageobject><imagedata fileref="linux_config.png" format="PNG"/></imageobject>
<textobject><phrase>xconfig Window</phrase></textobject></mediaobject></figure>
</listitem>
<listitem><para>To enable EVMS support, select
<guimenuitem>Enterprise Volume Management
System</guimenuitem>. The following window appears.</para>
<figure><title>Linux Kernel Configuration Window</title>
<mediaobject><imageobject><imagedata fileref="evms_config.png" format="PNG"/></imageobject>
<textobject><phrase>Linux Kernel Configuration Window</phrase>
</textobject></mediaobject></figure>
<note><title>NOTE</title>
<para>If you are configuring EVMS as
modules, you can click the <guibutton>Help</guibutton> button beside each
module to see the name of each kermel module.</para></note></listitem>
<listitem><para>Select <option>y</option> for the first three
options: <option>EVMS Kernel Runtime</option>, <option>EVMS Local Device Manager</option>, and
<option>EVMS DOS Segment Manager</option>. These options are the bare minimum for EVMS.
The remaining options add additional capabilities to EVMS.</para>
<note><title>NOTE</title>
<para>The options you select in this step are the ones you selected in <xref linkend="selectcapabilities"/>.</para></note>
</listitem>
<listitem><para>Select <option>y</option> for all additional options
you want to configure for EVMS. </para>
<note><title>NOTE</title>
<para>If you are configuring EVMS as modules,
select <option>m</option> for the first three options and all remaining
capabilities you wish to add.</para></note></listitem>
</orderedlist>
<para>Continue configuring your kernel as required for your
system and hardware. For general instructions on configuring
and compiling a Linux kernel, please see <ulink url="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> <citetitle>The Kernel HOWTO</citetitle></ulink>.</para>
<para>When you have finished configuring your
kernel, choose <guibutton>Save and Exit</guibutton> to quit
the kernel configuration.</para>
</sect1>
<sect1 id="buildinstall">
<title>Building and Installing the New Kernel</title>
<para>After you have configured the kernel, you will need to
build and install a new kernel image. There are slight variations for different architectures,
but the general steps are the same. For example, on Intel&reg; machines you could run
<command>lilo</command> to install the new kernel image. However , on S/390 machines, you
would run <command>zipl</command> to install the new kernel image. The following instructions
are based on an installation using an Intel machine. </para>
<orderedlist>
<listitem><para>Build the kernel :
<programlisting>
<![CDATA[
make dep clean bzImage modules modules_install
]]>
</programlisting>
</para></listitem>
<listitem><para>Copy the new kernel to the <filename>/boot</filename> directory.</para>
<programlisting>
<![CDATA[
cp /usr/src/linux/arch/i386/boot/bzImage /boot/vmlinuz-evms
]]>
</programlisting>
<note><title>NOTE</title>
<para>The command above assumes the file will be named
<filename>vmlinuz-evms</filename>, you can substitute
another name.</para></note></listitem>
<listitem><para>Open the file for the boot loader with your favorite editor.
The LILO boot loader information is in <filename>etc/lilo.conf</filename>.
The GRUB boot loader information is in <filename>boot/menu.list</filename>.</para></listitem>
<listitem><para>Update the boot loader information as follows:
<programlisting>
<![CDATA[
image=/boot/vmlinuz-evms
label=EVMS
append="root=/dev/evms/hda1"
]]>
</programlisting>
<note><title>NOTE</title>
<para>In order to have your boot partition on an EVMS controlled volume and use LILO,
you must have an EVMS patched version of
LILO or a version since 22.3.2. </para></note>
</para></listitem>
<listitem><para>Run your boot loader to install the new kernel image.</para>
<note><title>NOTE</title>
<para>If you installed your kernel as modules skip to
<xref linkend="INSTALLENGINE"/>. You will also need to
complete <xref linkend="INITRD"/> after building the engine.</para></note></listitem>
<listitem><para>Re-boot your machine and choose the new
kernel image to run with EVMS support.</para></listitem>
</orderedlist>
</sect1>
<!-- Installing the Engine -->
<sect1 id="INSTALLENGINE">
<title>Installing the Engine</title>
<para>The EVMS Engine consists of the user-space plug-ins and interfaces as well as a stand-alone
library, dlist, that the Engine uses for linked-list management.</para>
<sect2 id="installsource"><title>Installing from Source</title>
<orderedlist>
<listitem><para>To build and install the Engine from source, type the following commands:</para>
<programlisting>
cd /usr/src/evms-1.2.0/engine
autoconf
</programlisting>
<note><title>NOTE</title>
<para>The command <command>autoconf</command>
is necessary only for code taken directly from CVS.
However, using this command will not affect the build or
installation if your code is not taken directly from CVS.</para></note>
</listitem>
<listitem><para>Select the appropriate options for your configuration.
<note><title>NOTE</title>
<para>A list of options can be found by typing
<programlisting>./configure -h</programlisting></para></note>
</para>
</listitem>
<listitem><para>Configure your engine:
<programlisting>
./configure [--options]
</programlisting></para></listitem>
<listitem><para>Type the following commands:
<programlisting>
make
make install
ldconfig
</programlisting>
</para>
<para>Unless you specified other directories in Step 3, the
following list describes where files will be installed
on your system:
<itemizedlist>
<listitem><para>The core Engine library will be installed in
<filename>/usr/local/lib</filename>.</para></listitem>
<listitem><para>The core dlist library will be installed in
<filename>/usr/local/lib</filename>.</para></listitem>
<listitem><para>All plug-in libraries will be installed in
<filename>/usr/local/lib/evms</filename>.</para></listitem>
<listitem><para>All user interface binaries will be installed
in <filename>/usr/local/sbin</filename>.</para></listitem>
</itemizedlist></para>
</listitem>
<listitem><para>Add the Engine library path to your
<varname>LD_LIBRARY_PATH</varname> environment variable, or to
your <filename>/etc/ld.so.conf</filename> file. Do not add the
plug-in library path because the Engine will dynamically load
these libraries directly.</para></listitem>
</orderedlist>
<para>Begin using EVMS by typing <command>evmsgui</command>
to start the GUI, <command>evmsn</command> to
start the Ncurses UI, or <command>evms</command> to start the
command line interpreter.</para>
</sect2>
<sect2 id="INSTALLRPM"><title>Installing the Engine RPM</title>
<para>You can download an RPM with the latest compiled engine
binaries and libraries. This RPM is available on the project
<ulink url="http://www.sourceforge.net/projects/evms/">web site</ulink> along with the
source code package. The RPM is a
generic i386 RPM that should install on any system that uses
the RPM.</para>
<para>If you install the EVMS RPM, you will still need to
patch your kernel with EVMS support. </para>
</sect2>
<sect2 id="INSTALLDEBIAN"><title>Installing the EVMS Debian Packages</title>
<para>Debian packages of EVMS are maintained by Matt Zimmerman
at the <ulink url="http://www.debian.org">Debian</ulink> website.
You can download these packages for the <ulink url="http://packages.debian.org/testing/admin/evms.html">Woody
</ulink> (testing) release, or for the
<ulink url="http://packages.debian.org/unstable/admin/evms.html">Sid</ulink> (unstable) release.</para>
<para>For the Debian package you should patch and recompile your kernel in order to use
EVMS. Debian has a packaged version of the EVMS kernel patches,
that includes instructions for patching and building your kernel.</para>
</sect2>
</sect1>
<!-- init ramdisk -->
<sect1 id="INITRD"><title>Loading Modules with an Init-Ramdisk</title>
<para>If you built your EVMS kernel
plug-ins as modules and want your root
file system mounted on an EVMS volume (the only recommended way of using EVMS
built as kernel modules), you must add EVMS support
to your init-ramdisk. If you do not have an
init-ramdisk, general instructions for creating one are in the kernel source
tree in the file <filename>Documentation/initrd.txt</filename>. Some distributions include utilities for creating init-ramdisks. (See your distribution
for details.) If you do not want to use an
init-ramdisk but want your root filesystem on an EVMS volume, you should
compile all EVMS support directly into the kernel.</para>
<para>To modify your init-ramdisk,
decompress it using <command>gunzip</command> and mount it through a loopback
device. The following steps walk you through modifying your
init-ramdisk. The following commands are based on
the assumption that the init-ramdisk is mounted on <filename>/mnt/loop</filename>.</para>
<orderedlist>
<listitem><para>Once the init-ramdisk is mounted, copy the EVMS kernel modules
to it.</para>
<programlisting>
<![CDATA[
mkdir -p /mnt/loop/lib/modules/2.4.19/kernel/drivers/evms
cp /lib/modules/2.4.19/kernel/drivers/evms/*.o \
/mnt/loop/lib/modules/2.4.19/kernel/drivers/evms
]]>
</programlisting>
<note><title>NOTE</title>
<para>In the previous code, 2.4.19 is the
recommended version of the kernel. You can replace this version number with your kernel version.</para></note>
</listitem>
<listitem><para>Copy the
<command>evms_rediscover</command>
utility to the init-ramdisk. If you
are not using devfs, copy the
<command>evms_devnode_fixup</command> utility
as well.</para>
<programlisting>
<![CDATA[
cp /usr/local/sbin/evms_rediscover /mnt/loop/bin
cp /usr/local/sbin/evms_devnode_fixup /mnt/loop/bin
]]>
</programlisting>
<note><title>NOTE</title>
<para><command>evms_rediscover</command> and <command>evms_devnode_fixup</command>
are statically linked with the necessary libraries and will not need any additional dynamic
libraries added to the init-ramdisk.</para></note>
</listitem>
<listitem><para>Edit the
<filename>linuxrc</filename> script on your
init-ramdisk so that it loads all of the EVMS kernel
modules and calls <command>evms_rediscover</command>,
followed by <command>evms_ devnode_fixup</command> (if you are not
running devfs).</para></listitem>
<listitem><para>Add the following lines to the
<filename>linuxrc</filename> script. These
lines should be added to the
<filename>linuxrc</filename> script before the
root file system is mounted, so the root volume
will be discovered and available.</para>
<programlisting>
insmod evms
insmod evms_passthru
insmod ldev_mgr
insmod dos_part
# Add insmod commands for all EVMS modules copied in the step above.
evms_rediscover
evms_devnode_fixup # If not running devfs
</programlisting>
<note><title>NOTE</title>
<para>For the 2.5 kernel replace <filename>insmod dos_part</filename> with
<filename>insmod dos</filename> in the script above.</para></note> </listitem></orderedlist>
</sect1>
</chapter>

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<chapter id="evmsuglocating"><title>Locating and Fixing Device Files</title>
<para>In order for user-space programs to access EVMS
volumes, device files are created in the <filename>/dev/evms
</filename> directory for each volume that is exported by EVMS. Device files are created every time
the Engine is opened and saves changes, so you can always see the the current state of the volume configuration
in the <filename>/dev/evms</filename> directory.</para>
<para>A variety of namespaces exist within the <filename>/dev/evms</filename> directory. Each plug-in defines
and maintains its own namespace. The most common names will
be those of DOS segments. On a non-EVMS Linux system, disk drives and drive partitions appear as files in
<filename>/dev</filename>. The same names are maintained in EVMS by the
local device manager and the DOS segment manager. Corresponding device files are created in
<filename>/dev/evms</filename>. An example of the naming convention follows:</para>
<programlisting>
/dev/hda -> /dev/evms/hda
/dev/hda1 -> /dev/evms/hda1
/dev/sdb -> /dev/evms/sdb
/dev/sdb5 -> /dev/evms/sdb5
</programlisting>
<para>EVMS features create logical volumes with persistent names. The
names of these volumes are used to create the appropriate device
file in <filename>/dev/evms</filename>. For example, if an EVMS
snapshot was created and made into a volume named "Thursday_Snapshot," the file would appear
as <filename>/dev/evms/Thursday_Snapshot</filename>.</para>
<para>The Linux LVM plug-in is an example of a plug-in specific namespace
that uses its own namespace (<filename>/dev/evms/lvm</filename>). In
this directory, additional directories are created for each active
volume group. Device files representing the LVM logical volumes
are created in the appropriate group directory, as demonstrated in the following example:</para>
<programlisting>/dev/Group1/Volume1 -> /dev/evms/lvm/Group1/Volume1</programlisting>
<para>Namespaces exist for other plug-ins. Currently
the OS/2 LVM is in <filename>/dev/evms/os2</filename>, the
AIX LVM is in <filename>/dev/evms/aix</filename>, and the MD is in <filename>/dev/evms/md</filename>.</para>
<note><title>CAUTION</title>
<para>When using EVMS you should perform all filesystem mounts using the
EVMS device nodes. Failure to do so could result in loss of data when running EVMS configuration tools.</para></note>
<sect1 id="DEVFS"><title>devfs</title>
<para>EVMS supports the kernel device file system (devfs). If you have
devfs enabled in the kernel and mounted in your file system tree, you
will see the device files for your volumes immediately upon boot.
devfs is the preferred method for running EVMS
because it ensures that the minor
numbers EVMS dynamically assigns to compatibility volumes will never be
out of sync with the minor numbers of the device files for those volumes.</para>
</sect1>
<sect1 id="DEVNODEFIXUP"><title>Fixing EVMS Device Nodes</title>
<para>On systems that are not running devfs, the device nodes in the
<filename>/dev/evms</filename> directory might become out of sync
with the volumes that are exported by the EVMS
kernel. The following list details potential problems that could occur if you do
not use devfs: </para>
<itemizedlist>
<listitem><para>Nodes might not exist for volumes that are exported.</para></listitem>
<listitem><para>Nodes might have the wrong minor
number associated with them.</para></listitem>
<listitem><para>Nodes might exist for volumes that are no longer exported by the EVMS
kernel.</para></listitem>
</itemizedlist>
<para>Starting one of the user interfaces alleviates the problems listed above. The EVMS Engine will update the device nodes in
the <filename>/dev/evms</filename> so that the nodes agree with the volumes that are exported by
the EVMS kernel.</para>
<para>The <command>evms_devnode_fixup</command> program provides an alternative
means of fixing the device nodes in the <filename>/dev/evms</filename> directory by
updating the device nodes without the overhead of starting the Engine.</para>
<para><command>evms_devnode_fixup</command>
can be run as a daemon by specifying the <option>-d</option> option. In daemon mode,
<command>evms_devnode_fixup</command> will first fix the device nodes in the
<filename>/dev/evms</filename> directory. It then loops, waiting for
notifications of volume changes from the EVMS Runtime. On each notification,
<command>evms_devnode_fixup</command> fixes the device nodes in the
<filename>/dev/evms</filename> directory.</para>
</sect1>
</chapter>

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<chapter id="evmsmigrate"><title>Viewing Compatibility Volumes after Migrating</title>
<para>Migrating to EVMS allows you to have the flexibility of EVMS without losing the integrity of your existing data. EVMS discovers existing volume management volumes as compatibility volumes. After you have installed EVMS, you can view your existing volumes with the interface of your choice. </para>
<sect1 id="guimigrate"><title>Using the EVMS GUI</title>
<para>If you are using the EVMS GUI as your preferred interface, you can view your migrated volumes by typing <command>evmsgui</command> at the command prompt. The following screen appears listing your migrated volumes. </para>
<figure><title>GUI Start-up Window</title>
<mediaobject><imageobject><imagedata fileref="gui.png" format="PNG"/></imageobject>
<textobject><phrase>GUI start-up window</phrase></textobject></mediaobject></figure></sect1>
<sect1 id="ncurmigrate"><title>Using Ncurses</title>
<para>If you are using the Ncurses interface, you can view your migrated volumes by
typing <command>evmsn</command> at the command prompt. The following screen will
appear listing your migrated volumes. </para>
<figure><title>Ncurses Start-up Window</title>
<mediaobject>
<imageobject><imagedata fileref="n.png" format="PNG"/></imageobject>
<textobject>
<phrase>Ncurses Start-up Window</phrase></textobject></mediaobject></figure>
</sect1>
<sect1 id="climigrate"><title>Using the CLI</title>
<para>If you are using the Command Line Interpreter (CLI) interface, you can view
your migrated volumes by typing the following:</para>
<orderedlist><listitem><para>Start the Command Line Interpreter by typing
<command>evms</command> at the command line.</para></listitem>
<listitem><para>Query the volumes by typing the following at the
<prompt>EVMS</prompt> prompt:</para>
<programlisting>query:volumes</programlisting>
<para>Your migrated volumes are displayed as results of the
query. </para></listitem></orderedlist>
<figure><title>CLI Volume Query Results</title>
<mediaobject><imageobject><imagedata fileref="cli.png" format="PNG"/></imageobject>
<textobject><phrase>CLI Volume Query</phrase></textobject></mediaobject></figure>
</sect1>
<sect1 id="lvmmigrate"><title>Using Linux LVM Emulation Tools</title>
<para>If you are using the EVMS emulation of the Linux LVM command set, you can view
your Linux LVM migrated volumes by typing the following command:
<programlisting>evms_lvscan</programlisting></para>
<para>The following screen appears listing your migrated volumes.</para>
<figure><title>EVMS Emulation of Linux LVM</title>
<mediaobject><imageobject><imagedata fileref="lvm.png" format="PNG"/></imageobject>
<textobject><phrase>EVMS Emulation of Linux LVM to view Linux LVM volumes.</phrase></textobject></mediaobject></figure></sect1></chapter>

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<chapter id="intro"><title>What Is EVMS?</title>
<para>Enterprise Volume Management System (EVMS) brings a new model of volume management to Linux&reg;. EVMS integrates all aspects of volume management, such as disk partitioning, Linux logical volume manager (LVM) and multi-disk (MD) management, and filesystem operations into a single cohesive package. With EVMS, various volume managemet technologies are accessible through one interface, and new technologies can be added as they are developed. </para>
<sect1 id="cando"><title>Why Choose EVMS?</title>
<para>EVMS allows you to manage your storage space in a way that is more intuitive and flexible than many other Linux volume management systems. Practical tasks such as migrating disks or adding new disks to your Linux system become more managable with EVMS because of its ability to recognize and read from different volume types and filesystems. EVMS provides additional safety controls by not allowing unsafe commands. These controls help maintain the integrity of the data stored on the system. </para>
<para>You can use EVMS to create and manage data storage. With EVMS, you can use multiple volume management technologies under one framework. With one framework, you can access many technologies while ensuring your system will still interact correctly with stored data. With EVMS, you are able to use bad block relocation, shrink and expand volumes, create snapshots of your volumes, and set up RAID (redundant array of independent devices) features for your system. You are also able to use many types of filesystems and manipulate these storage pieces in ways that best meet your needs for your particular work environment. </para>
<para></para>
<para>EVMS provides a choice of user interfaces that allow you to manage your storage space. Additionally, if you need to design your own interface for EVMS, the system allows you to create customized interfaces. </para>
</sect1>
<sect1 id="uis"><title>Why Are There Different User Interfaces?</title>
<para>There are currently three user interfaces available for EVMS: graphical (GUI), text mode (Ncurses), and the Command Line Interpreter (CLI). You can use the EVMS Application Programming Interface to implement your own customized user interface. An example of a customized user interface is the EVMS emulation of the Linux LVM command set that comes standard with the EVMS download. </para>
<para><xref linkend="userinterf"/> lists details about each of the user interfaces and when each is appropriate.
</para>
<table id="userinterf" frame="all"><title>EVMS User Interfaces</title>
<tgroup cols="4">
<thead><row><entry>User Interface</entry>
<entry>Typical User</entry>
<entry>Types of Use</entry>
<entry>Function</entry></row></thead>
<tbody><row><entry>GUI</entry>
<entry>All</entry>
<entry>All uses except automation</entry>
<entry>Allows you to choose from available options only, instead of having to sort through all the options, including ones that are not available at that point in the process. </entry></row>
<row><entry>Ncurses</entry>
<entry>Users who don't have GTK libraries or X Window Systems on their machines</entry>
<entry>All uses except automation</entry>
<entry>Allows you to choose from available options only, instead of having to sort through all the options, including ones that are not available at that point in the process. </entry></row>
<row><entry>Command Line</entry>
<entry>Expert</entry>
<entry>All uses</entry>
<entry>Allows easy automation of tasks</entry></row>
<row><entry>LVM Emulation Tools</entry>
<entry>Experienced LVM User</entry>
<entry>LVM manipulation</entry>
<entry>Allows users to keep old scripts and knowledge base with only slight changes. </entry></row></tbody></tgroup>
</table>
</sect1>
<sect1 id="terminology">
<title>What Terms Does EVMS Use for Volume Management?</title>
<para>To avoid confusion with other terms used to describe volume
management, EVMS uses a set of terms specific to EVMS. The following list
defines volume management terms as they relate to EVMS. The terms
are listed from most fundamental to most comprehensive.
</para>
<variablelist>
<varlistentry><term>Logical Disk</term>
<listitem><para>Representation of anything EVMS can access as a physical disk.
In EVMS, physical disks are logical disks.</para></listitem>
</varlistentry>
<varlistentry><term>Sector</term>
<listitem><para>The lowest level of addressability on a block
device. This definition is in keeping with the standard
meaning found in other management systems.</para></listitem>
</varlistentry>
<varlistentry><term>Disk Segment</term>
<listitem><para>An ordered set of physically contiguous
sectors residing on the same storage object.
The general analogy for a segment is to a traditional disk
partition, such as DOS or OS/2 &reg;</para></listitem>
</varlistentry>
<varlistentry><term>Storage Region</term>
<listitem><para>An ordered set of logically contiguous sectors
that are not necessarily physically contiguous. </para></listitem>
</varlistentry>
<varlistentry><term>Storage Object</term>
<listitem><para>Any persistent memory structure in EVMS that can be used to
build objects or create a volume. Storage object is a generic term for disks, segments, regions, and feature objects.</para></listitem>
</varlistentry>
<varlistentry><term>Storage Container</term>
<listitem><para>A collection of storage objects. A storage
container consumes one set of storage objects and produces new
storage objects. One common subset of storage containers is volume groups,
such as AIX&reg; or LVM.</para></listitem>
</varlistentry>
<varlistentry><term>Feature Object</term>
<listitem><para>A storage object that contains an EVMS native feature, such as
bad block relocation. </para>
<para>An <glossterm>EVMS Native Feature</glossterm> is a function of volume management designed
and implemented by
EVMS. These features are not intended to be backwards compatible with other
volume management technologies. </para></listitem>
</varlistentry>
<varlistentry><term>Logical Volume</term>
<listitem><para>A volume that consumes a storage object and exports
something mountable. There are two varieties of logical volumes: <glossterm>EVMS Volumes</glossterm>
and <glossterm>Compatibility Volumes</glossterm>.</para>
<para> <glossterm>EVMS Volumes</glossterm> contain EVMS native metadata and can support all
EVMS features. <filename>/dev/evms/my_volume</filename> would be an example
of an EVMS Volume.</para>
<para><glossterm>Compatibility Volumes</glossterm> do not contain any EVMS native metadata.
Compatibility volumes are backward compatible to their particular scheme, but
they cannot support EVMS features. <filename>/dev/evms/md/md0</filename> would
be an example of a compatibility volume. </para></listitem>
</varlistentry>
</variablelist>
</sect1>
<sect1><title>What Makes EVMS So Flexible?</title>
<para>By dividing the labor between the Runtime and the Engine, EVMS reduces the size and kernel resources the system requires. The Runtime resides in kernel space and handles the actual use of the volumes. The Engine resides in user space and handles the creation, configuration, and management of volumes, segments, and disks. The EVMS Engine is a programmatic interface to the EVMS system. User interfaces and programs that use EVMS must go through the Engine. </para>
<para>EVMS provides the capacity for plug-in modules that allow EVMS to perform specialized tasks without altering the core code. These plug-in modules reside in kernel space and user space. A kernel space plug-in will have a corresponding user space plug-in module that provides the configuration and management tasks that are needed by the plug-in. The use of plug-in modules allow EVMS to be more extensible and customizable than other volume management systems. This design also allows EVMS to use only the resources needed to handle a volume. </para>
<sect2 id="LAYERDEF">
<title>Plug-in Layer Definitions</title>
<para>EVMS defines a layered architecture where plug-ins in each layer
create abstractions of the layer or layers below. EVMS also allows most plug-ins
to create abstractions of objects within the same layer. The following
list defines these layers from the bottom up.</para>
<variablelist termlength="15">
<varlistentry><term>Device Managers</term>
<listitem><para>The first layer is the device managers.
These plug-ins communicate with the hardware device drivers to
create the first EVMS objects. Currently, all devices are handled by a single plug-in.
Future releases of EVMS might need additional device managers
to do network device management, such as for disks on a storage
area network (SAN).</para></listitem>
</varlistentry>
<varlistentry><term>Segment Managers</term>
<listitem><para>The second layer is the segment managers. These plug-ins
handle the segmenting, or partitioning,
of disk drives. The Engine components can replace partitioning
programs, such as <command>fdisk</command> and
<application>Disk Druid</application>, and the kernel components
can replace the in-kernel disk partitioning code. Segment
managers can also be "stacked," meaning that one segment manager
can take as input output from another segment manager.</para>
<para> EVMS provides the following segment managers:
DOS, GPT, and System/390&reg; (S/390). Other segment manager
plug-ins can be added to support other
partitioning schemes.</para></listitem>
</varlistentry>
<varlistentry><term>Region Managers</term>
<listitem><para>The third layer is the region managers. This
layer is intended to provide a place for plug-ins that ensure
compatibility with existing volume management schemes in Linux
or other operating systems. Region managers are intended to
model systems that provide a logical abstraction above disks
or partitions.</para>
<para>Like the segment managers, region managers can also be
stacked. Therefore, the input object(s) to a region manager can
be disks, segments, or other regions.</para>
<para>There are currently four region manager plug-ins in EVMS:
Linux LVM, AIX, OS/2, and Multi-Disk (MD).
<variablelist><varlistentry><term>Linux LVM</term>
<listitem><para>The Linux LVM plug-in provides compatibility with
the Linux LVM and allows the creation of volume groups
(known in EVMS as containers) and logical volumes
(known in EVMS as regions). </para></listitem></varlistentry>
<varlistentry><term>AIX LVM</term>
<listitem><para>The AIX LVM provides compatibility with AIX and is similar in functionality
to the Linux LVM by also using volume groups and logical
volumes. </para></listitem></varlistentry>
<varlistentry><term>OS/2 LVM</term>
<listitem><para>The OS/2 plug-in provides compatibility with
volumes created under
OS/2. Unlike the Linux and AIX LVMs, the OS/2 LVM
is based on linear linking of disk partitions, as well as
bad-block relocation. The OS/2 LVM does not allow for modifications.</para></listitem></varlistentry>
<varlistentry><term>MD LVM</term>
<listitem><para>The Multi-Disk (MD) plug-in for RAID provides
RAID levels linear, 0, 1, 4, and 5 in
software. MD is one plug-in that will appear as four region
managers you will be able to choose from.</para></listitem></varlistentry>
</variablelist></para></listitem>
</varlistentry>
<varlistentry><term>EVMS Features</term>
<listitem><para>The next layer is EVMS features. This layer is
where new EVMS-native functionality is implemented. EVMS
features can be built on any object in the system, including
disks, segments, regions, or other feature objects. EVMS
features all share a common type of metadata, which makes
discovery of feature objects much more efficient, and recovery
of broken features objects much more reliable. There are three
features currently available in EVMS: Drive Linking, Bad Block Relocation,
and Snapshotting. </para>
<variablelist>
<varlistentry><term>Drive Linking</term>
<listitem><para>The Drive Linking feature allows any
number of objects to be linearly concatenated together into a
single object. A Drive Linked volume can be expanded by
adding another storage object to the end or shrunk by removing the last object.</para></listitem></varlistentry>
<varlistentry><term>Bad Block Relocation</term>
<listitem><para>The Bad Block Relocation (BBR) feature
monitors its I/O path and detects write failures (which can be
caused by a damaged disk). In the event of such a failure, the
data from that request is stored in a new location. BBR keeps
track of this remapping. Additional I/Os to that
location are redirected to the new location.</para></listitem></varlistentry>
<varlistentry><term>Snapshotting</term>
<listitem><para>The Snapshotting feature provides
a mechanism for creating a "frozen" copy of a volume at a single
instant in time, without having to take that volume off-line.
This is useful for performing backups on a live system.
Snapshots work with any volume (EVMS or compatibility), and can
use any other available object as a backing store. After a
snapshot is created and made into an EVMS volume, writes to the "original" volume cause the
original contents of that location to be copied to the snapshot's
storage object. Reads to the snapshot volume look like they
come from the original at the time the snapshot was created.
</para></listitem></varlistentry></variablelist>
</listitem>
</varlistentry>
<varlistentry><term>File System Interface Modules</term>
<listitem><para>File System Interface Modules (FSIMs) are
the one layer of EVMS that exists only in user space.
These plug-ins are used to provide coordination with the
filesystems during certain volume management operations. For
instance, when expanding or shrinking a volume, the filesystem
must also be expanded or shrunk to the appropriate size.
Ordering in this example is also important; a filesystem cannot
be expanded before the volume, and a volume cannot be shrunk
before the filesystem. The FSIMs allow EVMS to ensure this
coordination and ordering.</para>
<para>FSIMs also perform filesystem
operations from one of the EVMS user interfaces. For instance,
a user can make new filesystems and check existing filesystems
by interacting with the FSIM.</para></listitem>
</varlistentry>
</variablelist>
</sect2>
</sect1>
</chapter>

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<chapter id="evmsugpref">
<title>Preface</title>
<para>This book is designed to address user's questions about Enterprise Volume Management System (EVMS) and provide a context for using EVMS. </para>
<para>For additional information about EVMS or to ask questions specific to your distribution, the EVMS mailing lists are an excellent resource. You can view the list archives or subscribe to the lists from the <ulink url="http://evms.sourceforge.net/mailinglists.html">EVMS Project web site</ulink>. </para>
<para>Listed below are descriptions for the various sections of this User Guide.
<itemizedlist>
<listitem><para>Chapter 2: provides an oveview of some basic EVMS terms.</para></listitem>
<listitem><para>Chapter 3: explains how to download, install, and configure EVMS.</para></listitem>
<listitem><para>Chapter 4: reviews how to locate and fix <filename>/dev/</filename> files.</para></listitem>
<listitem><para>Chapter 5: introduces the EVMS interfaces and explains how to navigate through each. </para></listitem>
<listitem><para>Chapter 6: provides an overview of how to view your existing files after you migrate to EVMS.</para></listitem>
<listitem><para>Chapter 7: introduces the types of segment managers and describes how to apply segment managers to disks using the various EVMS interfaces.</para></listitem>
<listitem><para>Chapter 8-11: offers scenarios and explanations of how and why you would create the most fundamental pieces of the EVMS storage system. </para></listitem>
<listitem><para>Chapter 12: explains how to convert volumes from EVMS native volumes to compatibility volumes and from compatibility volumes to EVMS native volumes. </para></listitem>
</itemizedlist></para></chapter>

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