PERFORCE change 153545 for review
Rene Ladan
rene at FreeBSD.org
Tue Nov 25 11:00:45 PST 2008
http://perforce.freebsd.org/chv.cgi?CH=153545
Change 153545 by rene at rene_self on 2008/11/25 19:00:10
IFC
Affected files ...
.. //depot/projects/docproj_nl/en_US.ISO8859-1/books/handbook/geom/chapter.sgml#4 integrate
Differences ...
==== //depot/projects/docproj_nl/en_US.ISO8859-1/books/handbook/geom/chapter.sgml#4 (text+ko) ====
@@ -1,6 +1,6 @@
<!--
The FreeBSD Documentation Project
- $FreeBSD: doc/en_US.ISO8859-1/books/handbook/geom/chapter.sgml,v 1.43 2008/09/28 11:58:10 trhodes Exp $
+ $FreeBSD: doc/en_US.ISO8859-1/books/handbook/geom/chapter.sgml,v 1.44 2008/11/25 15:49:09 manolis Exp $
-->
@@ -147,7 +147,7 @@
<procedure>
<title>Creating a stripe of unformatted ATA disks</title>
- <step><para>Load the <filename>geom_stripe</filename>
+ <step><para>Load the <filename>geom_stripe.ko</filename>
module:</para>
<screen>&prompt.root; <userinput>kldload geom_stripe</userinput></screen>
@@ -167,13 +167,11 @@
for example <filename>/dev/ad2</filename> and
<filename>/dev/ad3</filename>:</para>
- <screen>&prompt.root; <userinput>gstripe label -v st0 /dev/ad2 /dev/ad3</userinput></screen>
+ <screen>&prompt.root; <userinput>gstripe label -v st0 /dev/ad2 /dev/ad3</userinput>
+Metadata value stored on /dev/ad2.
+Metadata value stored on /dev/ad3.
+Done.</screen>
-<!--
- <para>A message should be returned explaining that meta data has
- been stored on the devices.
-XXX: What message? Put it inside the screen output above.
--->
</step>
<step><para>Write a standard label, also known as a partition
@@ -206,12 +204,15 @@
<para>To mount this striped file system automatically during the boot
process, place the volume information in
- <filename>/etc/fstab</filename> file:</para>
+ <filename>/etc/fstab</filename> file. For this purpose, a permanent mount
+ point, named <filename class="directory">stripe</filename>, is
+ created:</para>
- <screen>&prompt.root; <userinput>echo "/dev/stripe/st0a /mnt ufs rw 2 2" \</userinput>
+ <screen>&prompt.root; <userinput>mkdir /stripe</userinput>
+&prompt.root; <userinput>echo "/dev/stripe/st0a /stripe ufs rw 2 2" \</userinput>
<userinput>>> /etc/fstab</userinput></screen>
- <para>The <filename>geom_stripe</filename> module must also be automatically loaded during
+ <para>The <filename>geom_stripe.ko</filename> module must also be automatically loaded during
system initialization, by adding a line to
<filename>/boot/loader.conf</filename>:</para>
@@ -290,9 +291,11 @@
<para>Edit the <filename>/etc/fstab</filename> file, replacing
references to the old <devicename>da0</devicename> with the
- new device nodes of the <devicename>gm0</devicename> mirror device.
- As the <username>root</username> user, edit the
- <filename>/etc/fstab</filename>:</para>
+ new device nodes of the <devicename>gm0</devicename> mirror device.</para>
+
+ <note>
+ <para>If &man.vi.1; is your preferred editor, the following is
+ an easy way to accomplish this task:</para>
<screen>&prompt.root; <userinput>vi /etc/fstab</userinput></screen>
@@ -302,6 +305,7 @@
replace all old <devicename>da0</devicename> references
with <devicename>gm0</devicename> by typing
<userinput>:%s/da/mirror\/gm/g</userinput>.<para>
+ </note>
<para>The resulting <filename>fstab</filename> file should look
similar to the following. It does not matter if the disk
@@ -380,7 +384,9 @@
OK? <userinput>boot</userinput></screen>
<para>If this works then for whatever reason the module was not
- being loaded properly. Place:</para>
+ being loaded properly. Check whether the relevant entry in
+ <filename>/boot/loader.conf</filename> is correct. If the problem
+ persists, place:</para>
<programlisting>options GEOM_MIRROR</programlisting>
@@ -518,27 +524,30 @@
<title>Label Types and Examples</title>
<para>There are two types of labels, a generic label and a
- file system label. The difference between the labels is
- the auto detection associated with permanent labels, and the
- fact that this type of label will be persistent across reboots.
- These labels are given a special directory in
+ file system label. Labels can be permanent or temporary.
+ Permanent labels can be created with the &man.tunefs.8;
+ or &man.newfs.8; commands. They will then be created
+ in a sub-directory of
<filename class="directory">/dev</filename>, which will be named
- based on their file system type. For example,
+ according to their file system type. For example,
<acronym>UFS</acronym>2 file system labels will be created in
the <filename class="directory">/dev/ufs</filename>
- directory.</para>
+ directory. Permanent labels can also be created with the
+ <command>glabel label</command> command. These are not file system
+ specific, and will be created in the <filename
+ class="directory">/dev/label</filename> directory.</para>
- <para>A generic label will go away with the next reboot. These
+ <para>A temporary label will go away with the next reboot. These
labels will be created in the
<filename class="directory">/dev/label</filename> directory and
- are perfect for experimentation.</para>
+ are perfect for experimentation. A temporary label can be
+ created using the <command>glabel create</command> command. For more
+ information, please read the manual page of &man.glabel.8;.</para>
<!-- XXXTR: How do you create a file system label without running newfs
or when there is no newfs (e.g.: cd9660)? -->
- <para>Permanent labels may be placed on the file system using the
- <command>tunefs</command> or <command>newfs</command>
- utilities. To create a permanent label for a
+ <para>To create a permanent label for a
<acronym>UFS</acronym>2 file system without destroying any
data, issue the following command:</para>
@@ -582,6 +591,65 @@
label:</para>
<screen>&prompt.root; <userinput>glabel destroy home</userinput></screen>
+
+ <para>The following example shows how to label the partitions of a
+ boot disk.</para>
+
+ <example>
+ <title>Labeling Partitions on the Boot Disk</title>
+
+ <para>By permanently labeling the partitions on the boot disk,
+ the system should be able to continue to boot normally, even
+ if the disk is moved to another controller or transferred
+ to a different system. For this example, it is assumed that a
+ single <acronym>ATA</acronym> disk is used, which is currently
+ recognized by the system as <devicename>ad0</devicename>. It is
+ also assumed that the standard &os; partition scheme is used, with
+ <filename class="directory">/</filename>,
+ <filename class="directory">/var</filename>,
+ <filename class="directory">/usr</filename> and
+ <filename class="directory">/tmp</filename> file systems, as well
+ as a swap partition.</para>
+
+ <para>Reboot the system, and at the &man.loader.8; prompt, press
+ <keycap>4</keycap> to boot into single user mode. Then enter the
+ following commands:</para>
+
+ <screen>&prompt.root; <userinput>glabel label rootfs /dev/ad0s1a</userinput>
+GEOM_LABEL: Label for provider /dev/ad0s1a is label/rootfs
+&prompt.root; <userinput>glabel label var /dev/ad0s1d</userinput>
+GEOM_LABEL: Label for provider /dev/ad0s1d is label/var
+&prompt.root; <userinput>glabel label usr /dev/ad0s1f</userinput>
+GEOM_LABEL: Label for provider /dev/ad0s1f is label/usr
+&prompt.root; <userinput>glabel label tmp /dev/ad0s1e</userinput>
+GEOM_LABEL: Label for provider /dev/ad0s1e is label/tmp
+&prompt.root; <userinput>glabel label swap /dev/ad0s1b</userinput>
+GEOM_LABEL: Label for provider /dev/ad0s1b is label/swap
+&prompt.root; <userinput>exit</userinput></screen>
+
+ <para>The system will continue with multi-user boot. After the boot
+ completes, edit <filename>/etc/fstab</filename> and replace the
+ conventional device names, with their respective labels. The
+ final <filename>/etc/fstab</filename> file will look like the
+ following:</para>
+
+ <programlisting># Device Mountpoint FStype Options Dump Pass#
+/dev/label/swap none swap sw 0 0
+/dev/label/rootfs / ufs rw 1 1
+/dev/label/tmp /tmp ufs rw 2 2
+/dev/label/usr /usr ufs rw 2 2
+/dev/label/var /var ufs rw 2 2</programlisting>
+
+ <para>The system can now be rebooted. If everything went well, it
+ will come up normally and <command>mount</command> will show:</para>
+
+ <screen>&prompt.root; <userinput>mount</userinput>
+/dev/label/rootfs on / (ufs, local)
+devfs on /dev (devfs, local)
+/dev/label/tmp on /tmp (ufs, local, soft-updates)
+/dev/label/usr on /usr (ufs, local, soft-updates)
+/dev/label/var on /var (ufs, local, soft-updates)</screen>
+ </example>
</sect2>
</sect1>
@@ -611,8 +679,9 @@
<para>This method is yet another mechanism to protect against data
loss and inconsistencies of the file system. Unlike Soft Updates
which tracks and enforces meta-data updates and Snapshots which
- is an image of the file system, an actual log is stored at the
- end sector and, in some cases, may be stored on another disk
+ is an image of the file system, an actual log is stored in disk
+ space specifically reserved for this task,
+ and in some cases may be stored on another disk
entirely.</para>
<para>Unlike other file system journaling implementations, the
@@ -626,6 +695,19 @@
<programlisting>options UFS_GJOURNAL</programlisting>
+ <para>If journaled volumes need to be mounted during startup, the
+ <filename>geom_journal.ko</filename> kernel module will also have to be
+ loaded, by adding the following line in
+ <filename>/boot/loader.conf</filename>:</para>
+
+ <programlisting>geom_journal_load="YES"</programlisting>
+
+ <para>Alternatively, this function can also be built into a custom
+ kernel, by adding the following line in the kernel configuration
+ file:</para>
+
+ <programlisting>options GEOM_JOURNAL</programlisting>
+
<para>Creating a journal on a free file system may now be done
using the following steps, considering that the
<devicename>da4</devicename> is a new <acronym>SCSI</acronym>
@@ -669,6 +751,11 @@
the actual journal but this does not protect against data loss
incurred as a result of misusing
<command>tunefs</command>.</para>
+
+ <para>It is also possible to journal the boot disk of a &os; system.
+ Please refer to the article <ulink
+ url="&url.articles.gjournal-desktop;">Implementing UFS Journaling on
+ a Desktop PC</ulink> for detailed instructions on this task.</para>
</sect1>
</chapter>
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