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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-21 10:29:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-21 10:29:12 -0700
commit8a392625b665c676a77c62f8608d10ff430bcb83 (patch)
tree4000a65d61baed73200e47f91dea5263ed16edd0 /Documentation
parent519f0141f1c42e2b8b59c7dea005cbf6095358e8 (diff)
parent4b80991c6cb9efa607bc4fd6f3ecdf5511c31bb0 (diff)
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Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (52 commits) md: Protect access to mddev->disks list using RCU md: only count actual openers as access which prevent a 'stop' md: linear: Make array_size sector-based and rename it to array_sectors. md: Make mddev->array_size sector-based. md: Make super_type->rdev_size_change() take sector-based sizes. md: Fix check for overlapping devices. md: Tidy up rdev_size_store a bit: md: Remove some unused macros. md: Turn rdev->sb_offset into a sector-based quantity. md: Make calc_dev_sboffset() return a sector count. md: Replace calc_dev_size() by calc_num_sectors(). md: Make update_size() take the number of sectors. md: Better control of when do_md_stop is allowed to stop the array. md: get_disk_info(): Don't convert between signed and unsigned and back. md: Simplify restart_array(). md: alloc_disk_sb(): Return proper error value. md: Simplify sb_equal(). md: Simplify uuid_equal(). md: sb_equal(): Fix misleading printk. md: Fix a typo in the comment to cmd_match(). ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/md.txt30
1 files changed, 29 insertions, 1 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt
index a8b4306..1da9d1b 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -236,6 +236,11 @@ All md devices contain:
writing the word for the desired state, however some states
cannot be explicitly set, and some transitions are not allowed.
+ Select/poll works on this file. All changes except between
+ active_idle and active (which can be frequent and are not
+ very interesting) are notified. active->active_idle is
+ reported if the metadata is externally managed.
+
clear
No devices, no size, no level
Writing is equivalent to STOP_ARRAY ioctl
@@ -292,6 +297,10 @@ Each directory contains:
writemostly - device will only be subject to read
requests if there are no other options.
This applies only to raid1 arrays.
+ blocked - device has failed, metadata is "external",
+ and the failure hasn't been acknowledged yet.
+ Writes that would write to this device if
+ it were not faulty are blocked.
spare - device is working, but not a full member.
This includes spares that are in the process
of being recovered to
@@ -301,6 +310,12 @@ Each directory contains:
Writing "remove" removes the device from the array.
Writing "writemostly" sets the writemostly flag.
Writing "-writemostly" clears the writemostly flag.
+ Writing "blocked" sets the "blocked" flag.
+ Writing "-blocked" clear the "blocked" flag and allows writes
+ to complete.
+
+ This file responds to select/poll. Any change to 'faulty'
+ or 'blocked' causes an event.
errors
An approximate count of read errors that have been detected on
@@ -332,7 +347,7 @@ Each directory contains:
for storage of data. This will normally be the same as the
component_size. This can be written while assembling an
array. If a value less than the current component_size is
- written, component_size will be reduced to this value.
+ written, it will be rejected.
An active md device will also contain and entry for each active device
@@ -381,6 +396,19 @@ also have
'check' and 'repair' will start the appropriate process
providing the current state is 'idle'.
+ This file responds to select/poll. Any important change in the value
+ triggers a poll event. Sometimes the value will briefly be
+ "recover" if a recovery seems to be needed, but cannot be
+ achieved. In that case, the transition to "recover" isn't
+ notified, but the transition away is.
+
+ degraded
+ This contains a count of the number of devices by which the
+ arrays is degraded. So an optimal array with show '0'. A
+ single failed/missing drive will show '1', etc.
+ This file responds to select/poll, any increase or decrease
+ in the count of missing devices will trigger an event.
+
mismatch_count
When performing 'check' and 'repair', and possibly when
performing 'resync', md will count the number of errors that are