commit c2a5a60adeb806530dcdf904387d07b5aeba22a7
Author: Jack Reed <jreed(a)redhat.com>
Date: Fri Dec 21 11:01:11 2012 +1000
Added more highlighting info to RAID creation procedure, and merged it with RAID
levels section
en-US/Create_Software_RAID-x86.xml | 78 ++++++++++++++++++++++++++++++------
1 files changed, 66 insertions(+), 12 deletions(-)
---
diff --git a/en-US/Create_Software_RAID-x86.xml b/en-US/Create_Software_RAID-x86.xml
index e766e67..b7faf9b 100644
--- a/en-US/Create_Software_RAID-x86.xml
+++ b/en-US/Create_Software_RAID-x86.xml
@@ -49,40 +49,94 @@
<step>
<para>
- A group of checkboxes will appear beneath the <guilabel>File
System</guilabel> dropdown menu, which is grayed out for RAID. Choose the RAID level
of the device by checking the appropriate boxes (refer to <xref
linkend="RAID_Levels-x86" /> for more information). Certain boxes may be
grayed out and labeled <guilabel>not enough disks</guilabel> if that RAID
level cannot be achieved with the available disks. The checkboxes required for each RAID
level are:
+ A group of checkboxes will appear beneath the <guilabel>File
System</guilabel> dropdown menu, which is grayed out for RAID. Choose the RAID level
of the device by checking the required boxes. The level will be displayed at the right
when these boxes have been checked.
+ </para>
+ <para>
+ Next to each checkbox, any disk space that will be gained or lost by selecting that
option will be displayed in red. Certain boxes may be grayed out and labeled
<guilabel>not enough disks</guilabel> if that RAID level cannot be achieved
with the available disks.
</para>
- <itemizedlist>
+ <para>
+ The checkboxes required for each RAID level are:
+ </para>
+ <variablelist>
+
+ <varlistentry>
+ <term>
+ <guilabel>Optimized</guilabel> = RAID0
+ </term>
<listitem>
<para>
- <guilabel>Optimized</guilabel> = RAID0
+ Distributes data across multiple storage devices. Level 0 RAIDs offer increased
performance over standard partitions, and can be used to pool the storage of multiple
devices into one large virtual device. Note that Level 0 RAIDS offer no redundancy and
that the failure of one device in the array destroys the entire array. RAID 0 requires at
least two RAID partitions.
+
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry>
+
+ <term>
+ <guilabel>Redundancy</guilabel> = RAID1
+ </term>
<listitem>
<para>
- <guilabel>Redundancy</guilabel> = RAID1
+ Mirrors the data on one storage device onto one or more other storage devices.
Additional devices in the array provide increasing levels of redundancy. RAID 1 requires
at least two RAID partitions.
+
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry>
+
+ <term>
+ <guilabel>Error detection</guilabel> = RAID4
+ </term>
<listitem>
<para>
- <guilabel>Error detection</guilabel> = RAID4
+ Distributes data across multiple storage devices, but uses one device in the
array to store parity information that safeguards the array in case any device within the
array fails. Because all parity information is stored on the one device, access to this
device creates a bottleneck in the performance of the array. RAID 4 requires at least
three RAID partitions.
+
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry>
+
+ <term>
+ <guilabel>Optimized</guilabel> and
<guilabel>Distributed</guilabel> = RAID5
+ </term>
<listitem>
<para>
- <guilabel>Optimized</guilabel> and
<guilabel>Distributed</guilabel> = RAID5
+ Distributes data and parity information across multiple storage devices. Level 5
RAIDs therefore offer the performance advantages of distributing data across multiple
devices, but do not share the performance bottleneck of level 4 RAIDs because the parity
information is also distributed through the array. RAID 5 requires at least three RAID
partitions.
+
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry>
+
+ <term>
+ <guilabel>Redundant</guilabel> = RAID6
+ </term>
<listitem>
<para>
- <guilabel>Redundant</guilabel> = RAID6
+ Level 6 RAIDs are similar to level 5 RAIDs, but instead of storing only one set
of parity data, they store two sets. RAID 6 requires at least four RAID partitions.
+
</para>
</listitem>
+ </varlistentry>
+
+ <varlistentry>
+
+ <term>
+ <guilabel>Redundancy</guilabel> and
<guilabel>Optimized</guilabel> = RAID10
+ </term>
<listitem>
<para>
- <guilabel>Redundancy</guilabel> and
<guilabel>Optimized</guilabel> = RAID10
+ Level 10 RAIDs are <firstterm>nested RAIDs</firstterm> or
<firstterm>hybrid RAIDs</firstterm>. Level 10 RAIDs are constructed by
distributing data over mirrored sets of storage devices. For example, a level 10 RAID
constructed from four RAID partitions consists of two pairs of partitions in which one
partition mirrors the other. Data is then distributed across both pairs of storage
devices, as in a level 0 RAID. RAID 10 requires at least four RAID partitions.
+
</para>
</listitem>
- </itemizedlist>
+ </varlistentry>
+
+ </variablelist>
</step>
<step>
<para>
@@ -101,16 +155,16 @@
</procedure>
- <section id="RAID_Levels-x86">
+ <!-- <section id="RAID_Levels-x86">
<title>RAID Levels</title>
<para>
RAID devices can be created at set levels. Each level distributes data in a specific
fashion and offers distinctive performance and protection features. The following is a
brief description of the available RAID levels.
</para>
- <xi:include href="Create_Software_RAID-common-itemizedlist-1.xml"
xmlns:xi="http://www.w3.org/2001/XInclude" />
+ <xi:include href="Create_Software_RAID-common-itemizedlist-1.xml"
xmlns:xi="http://www.w3.org/2001/XInclude" /> -->
<!-- RAID 0 — distributes data across multiple storage devices. -->
- </section>
+ <!-- </section> -->
</section>