diff options
author | NeilBrown <neilb@suse.de> | 2007-05-09 13:35:38 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 23:30:57 +0400 |
commit | 08a02ecd28bad35a47357e611044dcbeab06e3d7 (patch) | |
tree | 31050d686e58d55411f95c89204321aa2ea2b63a /Documentation | |
parent | 42b9bebe3fea3d3ce381bc6735a3fb50e6613f06 (diff) | |
download | linux-08a02ecd28bad35a47357e611044dcbeab06e3d7.tar.xz |
md: allow reshape_position for md arrays to be set via sysfs
"reshape_position" records how much progress has been made on a "reshape"
(adding drives, changing layout or chunksize).
When it is set, the number of drives, layout and chunksize can have
two possible values, an old an a new.
So allow these different values to be visible, and allow both old and new to
be set: Set the old ones first, then the reshape_position, then the new
values.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/md.txt | 72 |
1 files changed, 44 insertions, 28 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 2202f5dc8ac2..5818628207b5 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -178,6 +178,21 @@ All md devices contain: The size should be at least PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array + layout + The "layout" for the array for the particular level. This is + simply a number that is interpretted differently by different + levels. It can be written while assembling an array. + + reshape_position + This is either "none" or a sector number within the devices of + the array where "reshape" is up to. If this is set, the three + attributes mentioned above (raid_disks, chunk_size, layout) can + potentially have 2 values, an old and a new value. If these + values differ, reading the attribute returns + new (old) + and writing will effect the 'new' value, leaving the 'old' + unchanged. + component_size For arrays with data redundancy (i.e. not raid0, linear, faulty, multipath), all components must be the same size - or at least @@ -193,11 +208,6 @@ All md devices contain: 1.2 (newer format in varying locations) or "none" indicating that the kernel isn't managing metadata at all. - layout - The "layout" for the array for the particular level. This is - simply a number that is interpretted differently by different - levels. It can be written while assembling an array. - resync_start The point at which resync should start. If no resync is needed, this will be a very large number. At array creation it will @@ -259,29 +269,6 @@ All md devices contain: like active, but no writes have been seen for a while (safe_mode_delay). - sync_speed_min - sync_speed_max - This are similar to /proc/sys/dev/raid/speed_limit_{min,max} - however they only apply to the particular array. - If no value has been written to these, of if the word 'system' - is written, then the system-wide value is used. If a value, - in kibibytes-per-second is written, then it is used. - When the files are read, they show the currently active value - followed by "(local)" or "(system)" depending on whether it is - a locally set or system-wide value. - - sync_completed - This shows the number of sectors that have been completed of - whatever the current sync_action is, followed by the number of - sectors in total that could need to be processed. The two - numbers are separated by a '/' thus effectively showing one - value, a fraction of the process that is complete. - - sync_speed - This shows the current actual speed, in K/sec, of the current - sync_action. It is averaged over the last 30 seconds. - - As component devices are added to an md array, they appear in the 'md' directory as new directories named dev-XXX @@ -412,6 +399,35 @@ also have Note that the numbers are 'bit' numbers, not 'block' numbers. They should be scaled by the bitmap_chunksize. + sync_speed_min + sync_speed_max + This are similar to /proc/sys/dev/raid/speed_limit_{min,max} + however they only apply to the particular array. + If no value has been written to these, of if the word 'system' + is written, then the system-wide value is used. If a value, + in kibibytes-per-second is written, then it is used. + When the files are read, they show the currently active value + followed by "(local)" or "(system)" depending on whether it is + a locally set or system-wide value. + + sync_completed + This shows the number of sectors that have been completed of + whatever the current sync_action is, followed by the number of + sectors in total that could need to be processed. The two + numbers are separated by a '/' thus effectively showing one + value, a fraction of the process that is complete. + + sync_speed + This shows the current actual speed, in K/sec, of the current + sync_action. It is averaged over the last 30 seconds. + + suspend_lo + suspend_hi + The two values, given as numbers of sectors, indicate a range + within the array where IO will be blocked. This is currently + only supported for raid4/5/6. + + Each active md device may also have attributes specific to the personality module that manages it. These are specific to the implementation of the module and could |