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author | John W. Linville <linville@tuxdriver.com> | 2012-09-07 15:07:55 -0400 |
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committer | John W. Linville <linville@tuxdriver.com> | 2012-09-07 15:07:55 -0400 |
commit | fac805f8c198092de9a2842efd7f5022e2937b18 (patch) | |
tree | 7557809c373f97a343c427d8fded0696060394ce /Documentation/device-mapper/dm-raid.txt | |
parent | 2461c7d60f9f3821274e4acf9019cba8b82c94b5 (diff) | |
parent | f10723841e624c0726c70356b31d91befed01dd6 (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless
Diffstat (limited to 'Documentation/device-mapper/dm-raid.txt')
-rw-r--r-- | Documentation/device-mapper/dm-raid.txt | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt index 946c73342cde..1c1844957166 100644 --- a/Documentation/device-mapper/dm-raid.txt +++ b/Documentation/device-mapper/dm-raid.txt @@ -27,6 +27,10 @@ The target is named "raid" and it accepts the following parameters: - rotating parity N (right-to-left) with data restart raid6_nc RAID6 N continue - rotating parity N (right-to-left) with data continuation + raid10 Various RAID10 inspired algorithms chosen by additional params + - RAID10: Striped Mirrors (aka 'Striping on top of mirrors') + - RAID1E: Integrated Adjacent Stripe Mirroring + - and other similar RAID10 variants Reference: Chapter 4 of http://www.snia.org/sites/default/files/SNIA_DDF_Technical_Position_v2.0.pdf @@ -59,6 +63,28 @@ The target is named "raid" and it accepts the following parameters: logical size of the array. The bitmap records the device synchronisation state for each region. + [raid10_copies <# copies>] + [raid10_format near] + These two options are used to alter the default layout of + a RAID10 configuration. The number of copies is can be + specified, but the default is 2. There are other variations + to how the copies are laid down - the default and only current + option is "near". Near copies are what most people think of + with respect to mirroring. If these options are left + unspecified, or 'raid10_copies 2' and/or 'raid10_format near' + are given, then the layouts for 2, 3 and 4 devices are: + 2 drives 3 drives 4 drives + -------- ---------- -------------- + A1 A1 A1 A1 A2 A1 A1 A2 A2 + A2 A2 A2 A3 A3 A3 A3 A4 A4 + A3 A3 A4 A4 A5 A5 A5 A6 A6 + A4 A4 A5 A6 A6 A7 A7 A8 A8 + .. .. .. .. .. .. .. .. .. + The 2-device layout is equivalent 2-way RAID1. The 4-device + layout is what a traditional RAID10 would look like. The + 3-device layout is what might be called a 'RAID1E - Integrated + Adjacent Stripe Mirroring'. + <#raid_devs>: The number of devices composing the array. Each device consists of two entries. The first is the device containing the metadata (if any); the second is the one containing the |