source: chapter10/fstab.xml@ 16cd0963

11.3 11.3-rc1 12.0 12.0-rc1 12.1 12.1-rc1 bdubbs/gcc13 multilib renodr/libudev-from-systemd trunk xry111/arm64 xry111/arm64-12.0 xry111/clfs-ng xry111/loongarch xry111/loongarch-12.0 xry111/loongarch-12.1 xry111/mips64el xry111/pip3 xry111/rust-wip-20221008 xry111/update-glibc
Last change on this file since 16cd0963 was 16cd0963, checked in by Bruce Dubbs <bdubbs@…>, 19 months ago

Adjust instructions for /dev/shm when creating virtual filesystems.
Some host create /dev/shm as a tmpfs. Some have is as
a symlink to a location in another directory. This
change handles both cases.

The change to the sysV bootscripts now creates /dev/shm
as a separate tmpfs from /run. This makes LFS sysV and
systemd versions treat /dev/shm the same.

  • Property mode set to 100644
File size: 6.0 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../general.ent">
5 %general-entities;
6]>
7
8<sect1 id="ch-bootable-fstab">
9 <?dbhtml filename="fstab.html"?>
10
11 <title>Creating the /etc/fstab File</title>
12
13 <indexterm zone="ch-bootable-fstab">
14 <primary sortas="e-/etc/fstab">/etc/fstab</primary>
15 </indexterm>
16
17 <para>The <filename>/etc/fstab</filename> file is used by some programs to
18 determine where file systems are to be mounted by default, in which order, and
19 which must be checked (for integrity errors) prior to mounting. Create a new
20 file systems table like this:</para>
21
22<screen revision="sysv"><userinput>cat &gt; /etc/fstab &lt;&lt; "EOF"
23<literal># Begin /etc/fstab
24
25# file system mount-point type options dump fsck
26# order
27
28/dev/<replaceable>&lt;xxx&gt;</replaceable> / <replaceable>&lt;fff&gt;</replaceable> defaults 1 1
29/dev/<replaceable>&lt;yyy&gt;</replaceable> swap swap pri=1 0 0
30proc /proc proc nosuid,noexec,nodev 0 0
31sysfs /sys sysfs nosuid,noexec,nodev 0 0
32devpts /dev/pts devpts gid=5,mode=620 0 0
33tmpfs /run tmpfs defaults 0 0
34devtmpfs /dev devtmpfs mode=0755,nosuid 0 0
35tmpfs /dev/shm tmpfs nosuid,nodev 0 0
36
37# End /etc/fstab</literal>
38EOF</userinput></screen>
39
40<screen revision="systemd"><userinput>cat &gt; /etc/fstab &lt;&lt; "EOF"
41<literal># Begin /etc/fstab
42
43# file system mount-point type options dump fsck
44# order
45
46/dev/<replaceable>&lt;xxx&gt;</replaceable> / <replaceable>&lt;fff&gt;</replaceable> defaults 1 1
47/dev/<replaceable>&lt;yyy&gt;</replaceable> swap swap pri=1 0 0
48
49# End /etc/fstab</literal>
50EOF</userinput></screen>
51
52 <para>Replace <replaceable>&lt;xxx&gt;</replaceable>,
53 <replaceable>&lt;yyy&gt;</replaceable>, and <replaceable>&lt;fff&gt;</replaceable>
54 with the values appropriate for the system, for example, <filename
55 class="partition">sda2</filename>, <filename
56 class="partition">sda5</filename>, and <systemitem
57 class="filesystem">ext4</systemitem>. For details on the six
58 fields in this file, see <command>man 5 fstab</command>.</para>
59
60 <para>Filesystems with MS-DOS or Windows origin (i.e. vfat, ntfs, smbfs,
61 cifs, iso9660, udf) need a special option, utf8, in order for non-ASCII
62 characters in file names to be interpreted properly. For non-UTF-8 locales,
63 the value of <option>iocharset</option> should be set to be the same as the
64 character set of the locale, adjusted in such a way that the kernel
65 understands it. This works if the relevant character set definition (found
66 under File systems -&gt; Native Language Support when configuring the kernel)
67 has been compiled into the kernel or built as a module. However, if the
68 character set of the locale is UTF-8, the corresponding option
69 <option>iocharset=utf8</option> would make the file system case sensitive. To
70 fix this, use the special option <option>utf8</option> instead of
71 <option>iocharset=utf8</option>, for UTF-8 locales. The
72 <quote>codepage</quote> option is also needed for vfat and smbfs filesystems.
73 It should be set to the codepage number used under MS-DOS in your country.
74 For example, in order to mount USB flash drives, a ru_RU.KOI8-R user would
75 need the following in the options portion of its mount line in
76 <filename>/etc/fstab</filename>:</para>
77
78<screen><literal>noauto,user,quiet,showexec,codepage=866,iocharset=koi8r</literal></screen>
79
80 <para>The corresponding options fragment for ru_RU.UTF-8 users is:</para>
81
82<screen><literal>noauto,user,quiet,showexec,codepage=866,utf8</literal></screen>
83
84 <para>Note that using <option>iocharset</option> is the default for
85 <literal>iso8859-1</literal> (which keeps the file system case
86 insensitive), and the <option>utf8</option> option tells
87 the kernel to convert the file names using UTF-8 so they can be
88 interpreted in the UTF-8 locale.</para>
89
90 <!--note>
91 <para>In the latter case, the kernel emits the following message:</para>
92
93<screen><computeroutput>FAT: utf8 is not a recommended IO charset for FAT filesystems,
94 filesystem will be case sensitive!</computeroutput></screen>
95
96 <para>This negative recommendation should be ignored, since all other values
97 of the <quote>iocharset</quote> option result in wrong display of filenames in
98 UTF-8 locales.</para>
99 </note-->
100
101 <para>It is also possible to specify default codepage and iocharset values for
102 some filesystems during kernel configuration. The relevant parameters
103 are named
104 <quote>Default NLS Option</quote> (<option>CONFIG_NLS_DEFAULT)</option>,
105 <quote>Default Remote NLS Option</quote> (<option>CONFIG_SMB_NLS_DEFAULT</option>),
106 <quote>Default codepage for FAT</quote> (<option>CONFIG_FAT_DEFAULT_CODEPAGE</option>), and
107 <quote>Default iocharset for FAT</quote> (<option>CONFIG_FAT_DEFAULT_IOCHARSET</option>).
108 There is no way to specify these settings for the
109 ntfs filesystem at kernel compilation time.</para>
110
111 <para>It is possible to make the ext3 filesystem reliable across power
112 failures for some hard disk types. To do this, add the
113 <option>barrier=1</option> mount option to the appropriate entry in
114 <filename>/etc/fstab</filename>. To check if the disk drive supports
115 this option, run
116 <ulink url="&blfs-book;general/hdparm.html">hdparm</ulink>
117 on the applicable disk drive. For example, if:</para>
118
119<screen role="nodump"><userinput>hdparm -I /dev/sda | grep NCQ</userinput></screen>
120
121 <para>returns non-empty output, the option is supported.</para>
122
123 <para>Note: Logical Volume Management (LVM) based partitions cannot use the
124 <option>barrier</option> option.</para>
125
126</sect1>
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