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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-01 09:02:01 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-01 09:02:01 -0700 |
commit | fcff06c438b60f415af5983efe92811d6aa02ad1 (patch) | |
tree | 704f6598b2de60a86774bc5cf152d4f051bd2dc4 /Documentation | |
parent | 068535f1fef4c90aee23eb7b9b9a71c5b72d7cd0 (diff) | |
parent | 63f33b8dda88923487004b20fba825486d009e7b (diff) | |
download | op-kernel-dev-fcff06c438b60f415af5983efe92811d6aa02ad1.zip op-kernel-dev-fcff06c438b60f415af5983efe92811d6aa02ad1.tar.gz |
Merge branch 'for-next' of git://neil.brown.name/md
Pull md updates from NeilBrown.
* 'for-next' of git://neil.brown.name/md:
DM RAID: Add support for MD RAID10
md/RAID1: Add missing case for attempting to repair known bad blocks.
md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE.
md/raid1: don't abort a resync on the first badblock.
md: remove duplicated test on ->openers when calling do_md_stop()
raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
md/raid1: prevent merging too large request
md/raid1: read balance chooses idlest disk for SSD
md/raid1: make sequential read detection per disk based
MD RAID10: Export md_raid10_congested
MD: Move macros from raid1*.h to raid1*.c
MD RAID1: rename mirror_info structure
MD RAID10: rename mirror_info structure
MD RAID10: Fix compiler warning.
raid5: add a per-stripe lock
raid5: remove unnecessary bitmap write optimization
raid5: lockless access raid5 overrided bi_phys_segments
raid5: reduce chance release_stripe() taking device_lock
Diffstat (limited to 'Documentation')
-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 946c733..1c18449 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 |