377 lines
5.8 KiB
HTML
377 lines
5.8 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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>The root filesystem</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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REL="HOME"
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TITLE="Linux System Administrators Guide"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Overview of the Directory Tree"
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HREF="dir-tree-overview.html"><LINK
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REL="PREVIOUS"
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TITLE="Background"
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HREF="fs-background.html"><LINK
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REL="NEXT"
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TITLE="The /etc directory"
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HREF="etc-fs.html"></HEAD
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><BODY
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CLASS="SECT1"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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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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>Linux System Administrators 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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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="fs-background.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 3. Overview of the Directory Tree</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="etc-fs.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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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="ROOT-FS"
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></A
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>3.2. The root filesystem</H1
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><P
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>The root filesystem should generally be small, since
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it contains very critical files and a small, infrequently
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modified filesystem has a better chance of not getting corrupted.
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A corrupted root filesystem will generally mean that the system
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becomes unbootable except with special measures (e.g., from a
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floppy), so you don't want to risk it.</P
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><P
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>The root directory generally doesn't contain any files, except
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perhaps on older systems where the standard boot image for the system,
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usually called <TT
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CLASS="FILENAME"
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>/vmlinuz</TT
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>
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was kept there. (Most
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distributions have moved those files the the
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<TT
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CLASS="FILENAME"
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>/boot</TT
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> directory. Otherwise, all files are kept
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in subdirectories under the root filesystem:
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<DIV
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CLASS="GLOSSLIST"
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><DL
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/bin</TT
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></B
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></DT
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><DD
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><P
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>Commands needed during bootup
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that might be used by normal users (probably after
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bootup).</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/sbin</TT
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></B
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></DT
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><DD
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><P
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>Like <TT
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CLASS="FILENAME"
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>/bin</TT
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>, but the
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commands are not intended for normal users, although they
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may use them if necessary and allowed.
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<TT
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CLASS="FILENAME"
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>/sbin</TT
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> is not usually in the default
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path of normal users, but will be in root's default
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path.</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/etc</TT
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></B
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></DT
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><DD
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><P
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>Configuration files specific to the
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machine.</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/root</TT
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></B
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></DT
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><DD
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><P
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>The home directory for user root. This is
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usually not accessible to other users on the
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system</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/lib</TT
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></B
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></DT
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><DD
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><P
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>Shared libraries needed by the programs on
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the root filesystem.</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/lib/modules</TT
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></B
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></DT
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><DD
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><P
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>Loadable kernel modules, especially those
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that are needed to boot the system when recovering from
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disasters (e.g., network and filesystem
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drivers).</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/dev</TT
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></B
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></DT
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><DD
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><P
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>Device files. These are special files that
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help the user interface with the various devices on the system.
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</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/tmp</TT
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></B
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></DT
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><DD
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><P
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>Temporary files. As the name suggests,
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programs running often store temporary files in here.
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</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/boot</TT
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></B
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></DT
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><DD
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><P
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>Files used by the bootstrap loader,
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e.g., LILO or GRUB. Kernel images are often kept here instead
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of in the root directory. If there are many kernel
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images, the directory can easily grow rather big, and it
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might be better to keep it in a separate filesystem.
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Another reason would be to make sure the kernel
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images are within the first 1024 cylinders of an IDE
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disk. This 1024 cylinder limit is no longer true in
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most cases. With modern BIOSes and later versions of LILO
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(the LInux LOader) the 1024 cylinder limit can be passed
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with logical block addressing (LBA). See the
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<B
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CLASS="COMMAND"
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>lilo</B
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> manual page for more details.
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</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/mnt</TT
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></B
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></DT
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><DD
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><P
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>Mount point for temporary mounts by
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the system administrator. Programs aren't supposed to mount
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on <TT
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CLASS="FILENAME"
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>/mnt</TT
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> automatically.
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<TT
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CLASS="FILENAME"
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>/mnt</TT
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> might be divided into
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subdirectories (e.g., <TT
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CLASS="FILENAME"
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>/mnt/dosa</TT
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> might
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be the floppy drive using an MS-DOS filesystem, and
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<TT
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CLASS="FILENAME"
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>/mnt/exta</TT
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> might be the same
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with an ext2 filesystem).</P
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></DD
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><DT
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><B
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><TT
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CLASS="FILENAME"
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>/proc</TT
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>,
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<TT
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CLASS="FILENAME"
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>/usr</TT
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>,
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<TT
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CLASS="FILENAME"
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>/var</TT
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>,
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<TT
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CLASS="FILENAME"
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>/home</TT
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></B
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></DT
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><DD
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><P
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>Mount points for the other filesystems. Although
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<TT
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CLASS="FILENAME"
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>/proc</TT
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> does not reside on any disk in reality
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it is still mentioned here. See the section about
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<TT
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CLASS="FILENAME"
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>/proc</TT
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> later in the chapter.
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</P
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></DD
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></DL
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></DIV
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>
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</P
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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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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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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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><A
|
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HREF="fs-background.html"
|
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ACCESSKEY="P"
|
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>Prev</A
|
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></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
|
|
HREF="index.html"
|
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ACCESSKEY="H"
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>Home</A
|
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></TD
|
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><TD
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WIDTH="33%"
|
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ALIGN="right"
|
|
VALIGN="top"
|
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><A
|
|
HREF="etc-fs.html"
|
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ACCESSKEY="N"
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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%"
|
|
ALIGN="left"
|
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VALIGN="top"
|
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>Background</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="dir-tree-overview.html"
|
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ACCESSKEY="U"
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>Up</A
|
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></TD
|
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><TD
|
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WIDTH="33%"
|
|
ALIGN="right"
|
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VALIGN="top"
|
|
>The <TT
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CLASS="FILENAME"
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|
>/etc</TT
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> directory</TD
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></TR
|
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></TABLE
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></DIV
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></BODY
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></HTML
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> |