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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-09 01:28:33 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-09 01:28:33 +0400
commit2943c833222ef87c111ee0c6b7b8519ad2983e99 (patch)
tree0ef8cc4f72a63b325e7ae858ec68822ec4f3c64f /Documentation
parent98793265b429a3f0b3f1750e74d67cd4d740d162 (diff)
parent19d671695e1931ebfd75b2b888778201aefe35ca (diff)
downloadlinux-2943c833222ef87c111ee0c6b7b8519ad2983e99.tar.xz
Merge tag 'md-3.3' of git://neil.brown.name/md
md update for 3.3 Big change is new hot-replacement. A slot in an array can hold 2 devices - one that wants-replacement and one that is the replacement. Once the replacement is built - either from the original or (in the case of errors) from elsewhere, the wants-replacement device will be removed. * tag 'md-3.3' of git://neil.brown.name/md: (36 commits) md/raid1: Mark device want_replacement when we see a write error. md/raid1: If there is a spare and a want_replacement device, start replacement. md/raid1: recognise replacements when assembling arrays. md/raid1: handle activation of replacement device when recovery completes. md/raid1: Allow a failed replacement device to be removed. md/raid1: Allocate spare to store replacement devices and their bios. md/raid1: Replace use of mddev->raid_disks with conf->raid_disks. md/raid10: If there is a spare and a want_replacement device, start replacement. md/raid10: recognise replacements when assembling array. md/raid10: Allow replacement device to be replace old drive. md/raid10: handle recovery of replacement devices. md/raid10: Handle replacement devices during resync. md/raid10: writes should get directed to replacement as well as original. md/raid10: allow removal of failed replacement devices. md/raid10: preferentially read from replacement device if possible. md/raid10: change read_balance to return an rdev md/raid10: prepare data structures for handling replacement. md/raid5: Mark device want_replacement when we see a write error. md/raid5: If there is a spare and a want_replacement device, start replacement. md/raid5: recognise replacements when assembling array. ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/md.txt22
1 files changed, 18 insertions, 4 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt
index fc94770f44ab..993fba37b7d1 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -357,14 +357,14 @@ Each directory contains:
written to, that device.
state
- A file recording the current state of the device in the array
+ A file recording the current state of the device in the array
which can be a comma separated list of
faulty - device has been kicked from active use due to
- a detected fault or it has unacknowledged bad
- blocks
+ a detected fault, or it has unacknowledged bad
+ blocks
in_sync - device is a fully in-sync member of the array
writemostly - device will only be subject to read
- requests if there are no other options.
+ requests if there are no other options.
This applies only to raid1 arrays.
blocked - device has failed, and the failure hasn't been
acknowledged yet by the metadata handler.
@@ -374,6 +374,13 @@ Each directory contains:
This includes spares that are in the process
of being recovered to
write_error - device has ever seen a write error.
+ want_replacement - device is (mostly) working but probably
+ should be replaced, either due to errors or
+ due to user request.
+ replacement - device is a replacement for another active
+ device with same raid_disk.
+
+
This list may grow in future.
This can be written to.
Writing "faulty" simulates a failure on the device.
@@ -386,6 +393,13 @@ Each directory contains:
Writing "in_sync" sets the in_sync flag.
Writing "write_error" sets writeerrorseen flag.
Writing "-write_error" clears writeerrorseen flag.
+ Writing "want_replacement" is allowed at any time except to a
+ replacement device or a spare. It sets the flag.
+ Writing "-want_replacement" is allowed at any time. It clears
+ the flag.
+ Writing "replacement" or "-replacement" is only allowed before
+ starting the array. It sets or clears the flag.
+
This file responds to select/poll. Any change to 'faulty'
or 'blocked' causes an event.