292 lines
5.3 KiB
HTML
292 lines
5.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>EVMS terminology</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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TITLE="EVMS User Guide"
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TITLE="What is EVMS?"
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HREF="intro.html"><LINK
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TITLE="The EVMS user interfaces"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>EVMS User Guide</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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><TD
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>Chapter 1. What is EVMS?</TD
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><TD
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="terminology"
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></A
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>1.3. EVMS terminology</H1
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><P
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>To avoid confusion with other terms that describe volume
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management in general, EVMS uses a specific set of terms.
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These terms are listed, from most fundamental to most comprehensive,
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as follows:
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</P
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><P
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></P
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><DIV
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CLASS="variablelist"
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><DL
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><DT
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>Logical disk</DT
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><DD
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><P
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>Representation of anything EVMS can access as a physical disk.
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In EVMS, physical disks are logical disks.</P
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></DD
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><DT
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>Sector</DT
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><DD
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><P
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>The lowest level of addressability on a block
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device. This definition is in keeping with the standard
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meaning found in other management systems.</P
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></DD
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><DT
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>Disk segment</DT
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><DD
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><P
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>An ordered set of physically contiguous
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sectors residing on the same storage object.
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The general analogy for a segment is to a traditional disk
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partition, such as DOS or OS/2 ®</P
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></DD
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><DT
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>Storage region</DT
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><DD
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><P
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>An ordered set of logically contiguous sectors
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that are not necessarily physically contiguous. </P
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></DD
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><DT
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>Storage object</DT
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><DD
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><P
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>Any persistent memory structure in EVMS that can be used to
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build objects or create a volume. Storage object is a generic term for disks, segments, regions, and feature objects.</P
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></DD
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><DT
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>Storage container</DT
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><DD
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><P
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>A collection of storage objects. A storage
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container consumes one set of storage objects and produces new
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storage objects. One common subset of storage containers is volume groups,
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such as AIX® or LVM.</P
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><P
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>Storage containers can be either of type private or cluster.</P
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></DD
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><DT
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>Cluster storage container</DT
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><DD
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><P
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>Specialized storage containers that consume only disk objects
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that are physically accessible from all nodes of a cluster.</P
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><P
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></P
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><DIV
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CLASS="variablelist"
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><DL
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><DT
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>Private storage container</DT
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><DD
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><P
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>A collection of disks that are physically accessible from all
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nodes of a cluster, managed as a single pool of storage, and owned and accessed
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by a single node of the cluster at any given time.</P
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></DD
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><DT
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>Shared storage container</DT
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><DD
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><P
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>A collection of disks that are physically accessible from all
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nodes of a cluster, managed as a single pool of storage, and owned and accessed
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by all nodes of the cluster simultaneously.</P
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></DD
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><DT
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>Deported storage container</DT
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><DD
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><P
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>A shared cluster container that is not owned by any node of the cluster.</P
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></DD
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></DL
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></DIV
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></DD
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><DT
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>Feature object</DT
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><DD
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><P
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>A storage object that contains an EVMS native feature.
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</P
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><P
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>An <I
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CLASS="glossterm"
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>EVMS Native Feature</I
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> is a function of volume management designed
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and implemented by
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EVMS. These features are not intended to be backward compatible with other
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volume management technologies. </P
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></DD
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><DT
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>Logical volume</DT
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><DD
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><P
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>A volume that consumes a storage object and exports
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something mountable. There are two varieties of logical volumes: <I
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CLASS="glossterm"
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>EVMS Volumes</I
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>
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and <I
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CLASS="glossterm"
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>Compatibility volumes</I
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>.</P
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><P
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> <I
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CLASS="glossterm"
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>EVMS Volumes</I
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> contain EVMS native metadata and can support all
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EVMS features. <TT
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CLASS="filename"
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>/dev/evms/my_volume</TT
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> would be an example
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of an EVMS Volume.</P
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><P
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><I
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CLASS="glossterm"
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>Compatibility volumes</I
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> do not contain any EVMS native metadata.
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Compatibility volumes are backward compatible to their particular scheme, but
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they cannot support EVMS features. <TT
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CLASS="filename"
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>/dev/evms/md/md0</TT
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> would
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be an example of a compatibility volume. </P
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></DD
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></DL
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></DIV
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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>Prev</A
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>Home</A
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HREF="x262.html"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
|
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>The EVMS user interfaces</TD
|
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><TD
|
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="intro.html"
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ACCESSKEY="U"
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>Up</A
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
|
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>What makes EVMS so flexible?</TD
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></TR
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