From 499917c9d16990bd0114777ed5b1529fde5aea08 Mon Sep 17 00:00:00 2001 From: Frans Pop Date: Thu, 25 Sep 2008 19:12:58 +0000 Subject: Apply patch from Ryan Niebur to document RAID6 and RAID10 support (after review and minor changes) --- en/using-d-i/modules/mdcfg.xml | 75 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) (limited to 'en/using-d-i/modules') diff --git a/en/using-d-i/modules/mdcfg.xml b/en/using-d-i/modules/mdcfg.xml index e1ebb161a..9db8184c5 100644 --- a/en/using-d-i/modules/mdcfg.xml +++ b/en/using-d-i/modules/mdcfg.xml @@ -93,6 +93,42 @@ while achieving less redundancy. On the other hand, it might be a bit slower on write operations than RAID0 due to computation of parity information. + + + + +RAID6 + +Is similar to RAID5 except that it uses two parity devices instead of +one. + + + +A RAID6 array can survive up to two disk failures. + + + + + +RAID10 + +RAID10 combines striping (as in RAID0) and mirroring (as 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. + + + +RAID10 can be used to achieve reliability and redundancy without the +drawback of having to calculate parity. + @@ -139,6 +175,27 @@ To sum it up: + + RAID6 + 4 + optional + yes + + Size of the smallest partition multiplied by (number of devices in + RAID minus two) + + + + + RAID10 + 2 + optional + yes + + Total of all partitions divided by the number of chunk copies (defaults to two) + + + @@ -213,6 +270,24 @@ continue until you correct the issue. RAID5 has a similar setup procedure as RAID1 with the exception that you need to use at least three active partitions. + + + +RAID6 also has a similar setup procedure as RAID1 except thatat least +four active partitions are required. + + + + +RAID10 again has a similar setup procedure as RAID1 except in expert +mode. In expert mode, &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 all of the copies can be distributed onto +different disks. + -- cgit v1.2.3