Update of the installation-guide with RAID 6 and 10
Ryan Niebur
ryanryan52 at gmail.com
Sat Aug 23 10:08:57 UTC 2008
On Sat, Aug 16, 2008 at 09:19:54PM +0200, Jérémy Bobbio wrote:
> Hi!
>
> Thanks for your patches which enabled support for RAID levels 6 and 10
> in the debian-installer.
>
> Unfortunately, these changes are currently not documented in the
> installation manual. It would be great if you could try to add the
> missing part and generally update those two files of the d-i repository:
>
> manual/en/appendix/preesed.xml
> manual/en/using-d-i/modules/mdcfg.xml
>
> Thanks in advance for any help in keeping the manual up to date…
>
Attached is a patch that documents RAID 6 and 10.
> Cheers,
> --
> Jérémy Bobbio .''`.
> lunar at debian.org : :Ⓐ : # apt-get install anarchism
> `. `'`
> `-
--
_________________________
Ryan Niebur
RyanRyan52 at gmail.com
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diff --git a/manual/debian/changelog b/manual/debian/changelog
index 0e7d2b1..276571d 100644
--- a/manual/debian/changelog
+++ b/manual/debian/changelog
@@ -17,6 +17,9 @@ installation-guide (2008xxxx) UNRELEASED; urgency=medium
automatically work w/o it if there's just 1 disk. Closes: #490287
* Document hw-detect/load_firmware. Closes: #493845
+ [ Ryan Niebur ]
+ * Added documentation for RAID 6 and 10
+
-- Frans Pop <fjp at debian.org> Wed, 02 Jul 2008 17:06:28 +0200
installation-guide (20080520) unstable; urgency=medium
diff --git a/manual/en/appendix/preseed.xml b/manual/en/appendix/preseed.xml
index 2e0b41a..d5ae0f7 100644
--- a/manual/en/appendix/preseed.xml
+++ b/manual/en/appendix/preseed.xml
@@ -993,7 +993,7 @@ d-i partman/confirm boolean true
<para>
You can also use preseeding to set up partitions on software RAID arrays.
-Supported are RAID levels 0, 1 and 5, creating degraded arrays and
+Supported are RAID levels 0, 1, 5, 6 and 10, creating degraded arrays and
specifying spare devices.
If you are using RAID 1, you can preseed grub to install to all devices
used in the array; see <xref linkend="preseed-bootloader"/>.
@@ -1044,7 +1044,7 @@ spare devices has only been tested lightly.
# Parameters are:
# <raidtype> <devcount> <sparecount> <fstype> <mountpoint> \
# <devices> <sparedevices>
-# RAID levels 0, 1 and 5 are supported; devices are separated using "#"
+# RAID levels 0, 1, 5, 6 and 10 are supported; devices are separated using "#"
#d-i partman-auto-raid/recipe string \
# 1 2 0 ext3 / \
# /dev/discs/disc0/part1#/dev/discs/disc1/part1 \
diff --git a/manual/en/using-d-i/modules/mdcfg.xml b/manual/en/using-d-i/modules/mdcfg.xml
index e1ebb16..ec94659 100644
--- a/manual/en/using-d-i/modules/mdcfg.xml
+++ b/manual/en/using-d-i/modules/mdcfg.xml
@@ -95,6 +95,41 @@ information.
</para></listitem>
</varlistentry>
+<varlistentry>
+
+<term>RAID6</term><listitem><para>
+
+Is similar to RAID5 except that it uses two parity devices instead of
+one.
+
+</para><para>
+
+A RAID6 array can survive up to two disk failures.
+
+</para></listitem>
+</varlistentry>
+<varlistentry>
+
+<term>RAID10</term><listitem><para>
+
+RAID10 combines striping (like in RAID0) and mirroring (like in
+RAID1). It creates n copies of incoming data and distributes them
+across the partitions so that none of the copies of the same data are
+on the same device. The default value of n is 2, but it can be set to
+something else in expert mode. The number of partitions used must be
+at least n. RAID10 has different layouts for distributing the
+copies. The default is near copies. Near copies have all of the copies
+at about the same offset on all of the disks. Far copies have the
+copies at different offsets on the disks. Offset copies copy the
+stripe, not the individual copies.
+
+</para><para>
+
+RAID10 can be used to achieve reliability and redundancy without the
+drawback of having to calculate parity.
+
+</para></listitem>
+</varlistentry>
</variablelist>
To sum it up:
@@ -139,6 +174,27 @@ To sum it up:
</entry>
</row>
+<row>
+ <entry>RAID6</entry>
+ <entry>4</entry>
+ <entry>optional</entry>
+ <entry>yes</entry>
+ <entry>
+ Size of the smallest partition multiplied by (number of devices in
+ RAID minus two)
+ </entry>
+</row>
+
+<row>
+ <entry>RAID10</entry>
+ <entry>2</entry>
+ <entry>optional</entry>
+ <entry>yes</entry>
+ <entry>
+ Total of all partitions divided by the number of chunk copies (defaults to two)
+ </entry>
+</row>
+
</tbody></tgroup></informaltable>
</para><para>
@@ -214,6 +270,23 @@ RAID5 has a similar setup procedure as RAID1 with the exception that you
need to use at least <emphasis>three</emphasis> active partitions.
</para></listitem>
+<listitem><para>
+
+RAID6 has a similar setup procedure as RAID1 with the exception that you
+need to use at least <emphasis>four</emphasis> active partitions.
+
+</para></listitem>
+<listitem><para>
+
+RAID10 has a similar setup procedure as RAID1 except in expert
+mode. In expert mode, the &d-i; will ask you for the layout. The
+layout has two parts. The first part is the layout type. It is either n
+(for near copies), f (for far copies), or o (for offset copies). The
+second part is the number of copies to make of the data. There must be
+at least that many active devices so that it can distribute all of the
+copies onto different disks.
+
+</para></listitem>
</itemizedlist>
<para>
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