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2016-10-24docs-rst: create an user's manual bookMauro Carvalho Chehab1-727/+0
Place README, REPORTING-BUGS, SecurityBugs and kernel-parameters on an user's manual book. As we'll be numbering the user's manual, remove the manual numbering from SecurityBugs. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24Documentation/md.txt: Convert to ReST markupMauro Carvalho Chehab1-207/+321
- add a title for the document; - convert some parameters to tables; - use quote blocks where needed; - use monotonic fonts for parameters; - adjust whitespaces and blank lines; - add it to the user's book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-23Documentation: fix wrong value in md.txtTiezhu Yang1-1/+1
In the current Documentation/md.txt, the lower limit value of stripe_cache_size is 16 and the default value is 128, but when I update kernel to the latest mainline version and RAID5 array is created by mdadm, then execute the following commands, it shows an error and a difference respectively. 1) set stripe_cache_size to 16 [root@localhost ~]# echo 16 > /sys/block/md0/md/stripe_cache_size bash: echo: write error: Invalid argument 2) read the default value of stripe_cache_size [root@localhost ~]# cat /sys/block/md0/md/stripe_cache_size 256 I read drivers/md/raid5.c and find the following related code: 1) in function 'raid5_set_cache_size': if (size <= 16 || size > 32768) return -EINVAL; 2) #define NR_STRIPES 256 So the lower limit value of stripe_cache_size should be 17 and the default value should be 256. Signed-off-by: Tiezhu Yang <kernelpatch@126.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-06-23doc:md: fix typo in md.txt.Wei Fang1-1/+1
Signed-off-by: Wei Fang <fangwei1@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2013-12-02doc: fix some typos in documentationsXishi Qiu1-1/+1
Fix some typos in five documentations, no functional change. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Acked-by: Rob Landley <rob@landley.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-03md: remove doubled description for sync_max, merging it within sync_min/sync_maxCoolCold1-7/+6
After last md.txt edits for sync_min/max, sync_max description became doubled. Removing 1st copy, merging details into common sync_min/sync_max section. Signed-off-by: Roman Ovchinnikov <coolthecold@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24MD: Fix typos in MD documentationJonathan Brassow1-8/+8
MD: Fix some typos/grammer in MD documentation Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23md: create externally visible flags for supporting hot-replace.NeilBrown1-4/+18
hot-replace is a feature being added to md which will allow a device to be replaced without removing it from the array first. With hot-replace a spare can be activated and recovery can start while the original device is still in place, thus allowing a transition from an unreliable device to a reliable device without leaving the array degraded during the transition. It can also be use when the original device is still reliable but it not wanted for some reason. This will eventually be supported in RAID4/5/6 and RAID10. This patch adds a super-block flag to distinguish the replacement device. If an old kernel sees this flag it will reject the device. It also adds two per-device flags which are viewable and settable via sysfs. "want_replacement" can be set to request that a device be replaced. "replacement" is set to show that this device is replacing another device. The "rd%d" links in /sys/block/mdXx/md only apply to the original device, not the replacement. We currently don't make links for the replacement - there doesn't seem to be a need. Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md: update documentation for md/rdev/state sysfs interfaceNamhyung Kim1-5/+9
Previous patches in the bad block series extended behavior of rdev's 'state' interface but lacked documentation update. Fix it. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28md: add documentation for bad block logNamhyung Kim1-1/+14
Previous patch in the bad block series added new sysfs interfaces ([unacknowledged_]bad_blocks) for each rdev without documentation. Add it. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09md:Documentation/md.txt - fix typoNeilBrown1-1/+1
Reported-by: CoolCold <coolthecold@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20md: Update documentation for sync_min and sync_max entriesCoolCold1-0/+10
linux/Documentation/md.txt is missing description for sync_min and sync_max entries. This patch adds description for sync_min and sync_max entries. Signed-off-by: Roman Ovchinnikov <coolthecold@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-04Documentation: update broken web addresses.Justin P. Mattock1-1/+1
Below you will find an updated version from the original series bunching all patches into one big patch updating broken web addresses that are located in Documentation/* Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult, the best way to deal with these is to use web.archive.org to locate these addresses that are outdated. Now there are also some addresses pointing to .spec files some are located, but some(after searching on the companies site)where still no where to be found. In this case I just changed the address to the company site this way the users can contact the company and they can locate them for the users. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Thomas Weber <weber@corscience.de> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-04-23Documentation/: it's -> its where appropriateFrancis Galiegue1-1/+1
Fix obvious cases of "it's" being used when "its" was meant. Signed-off-by: Francis Galiegue <fgaliegue@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-14md: add 'recovery_start' per-device sysfs attributeDan Williams1-4/+23
Enable external metadata arrays to manage rebuild checkpointing via a md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset Also update resync_start_store to allow 'none' to be written, for consistency. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: Support write-intent bitmaps with externally managed metadata.NeilBrown1-0/+16
In this case, the metadata needs to not be in the same sector as the bitmap. md will not read/write any bitmap metadata. Config must be done via sysfs and when a recovery makes the array non-degraded again, writing 'true' to 'bitmap/can_clear' will allow bits in the bitmap to be cleared again. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: support updating bitmap parameters via sysfs.NeilBrown1-0/+29
A new attribute directory 'bitmap' in 'md' is created which contains files for configuring the bitmap. 'location' identifies where the bitmap is, either 'none', or 'file' or 'sector offset from metadata'. Writing 'location' can create or remove a bitmap. Adding a 'file' bitmap this way is not yet supported. 'chunksize' and 'time_base' must be set before 'location' can be set. 'chunksize' can be set before creating a bitmap, but is currently always over-ridden by the bitmap superblock. 'time_base' and 'backlog' can be updated at any time. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-03-31Documentation/md.txt updateNeilBrown1-7/+30
Update md.txt to reflect recent changes in a number of sysfs attributes. Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-21md: Tidy up rdev_size_store a bit:Neil Brown1-1/+1
- used strict_strtoull in place of simple_strtoull - use my_mddev in place of rdev->mddev (they have the same value) and more significantly, - don't adjust mddev->size to fit, rather reject changes which make rdev->size smaller than mddev->size Adjusting mddev->size is a hangover from bind_rdev_to_array which does a similar thing. But it really is a better design to insist that mddev->size is set as required, then the rdev->sizes are set to allow for that. The previous way invites confusion. Signed-off-by: NeilBrown <neilb@suse.de>
2008-06-28Make sure all changes to md/dev-XX/state are notifiedNeil Brown1-0/+10
The important state change happens during an interrupt in md_error. So just set a flag there and call sysfs_notify later in process context. Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28Make sure all changes to md/degraded are notified.Neil Brown1-0/+7
When a device fails, when a spare is activated, when an array is reshaped, or when an array is started, the extent to which the array is degraded can change. Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28Make sure all changes to md/sync_action are notified.Neil Brown1-0/+6
When the 'resync' thread starts or stops, when we explicitly set sync_action, or when we determine that there is definitely nothing to do, we notify sync_action. To stop "sync_action" from occasionally showing the wrong value, we introduce a new flags - MD_RECOVERY_RECOVER - to say that a recovery is probably needed or happening, and we make sure that we set MD_RECOVERY_RUNNING before clearing MD_RECOVERY_NEEDED. Signed-off-by: Neil Brown <neilb@suse.de>
2008-06-28Make sure all changes to md/array_state are notified.Neil Brown1-0/+5
Changes in md/array_state could be of interest to a monitoring program. So make sure all changes trigger a notification. Exceptions: changing active_idle to active is not reported because it is frequent and not interesting. changing active to active_idle is only reported on arrays with externally managed metadata, as it is not interesting otherwise. Signed-off-by: Neil Brown <neilb@suse.de>
2008-04-28md: introduce get_priority_stripe() to improve raid456 write performanceDan Williams1-0/+6
Improve write performance by preventing the delayed_list from dumping all its stripes onto the handle_list in one shot. Delayed stripes are now further delayed by being held on the 'hold_list'. The 'hold_list' is bypassed when: * a STRIPE_IO_STARTED stripe is found at the head of 'handle_list' * 'handle_list' is empty and i/o is being done to satisfy full stripe-width write requests * 'bypass_count' is less than 'bypass_threshold'. By default the threshold is 1, i.e. every other stripe handled is a preread stripe provided the top two conditions are false. Benchmark data: System: 2x Xeon 5150, 4x SATA, mem=1GB Baseline: 2.6.24-rc7 Configuration: mdadm --create /dev/md0 /dev/sd[b-e] -n 4 -l 5 --assume-clean Test1: dd if=/dev/zero of=/dev/md0 bs=1024k count=2048 * patched: +33% (stripe_cache_size = 256), +25% (stripe_cache_size = 512) Test2: tiobench --size 2048 --numruns 5 --block 4096 --block 131072 (XFS) * patched: +13% * patched + preread_bypass_threshold = 0: +37% Changes since v1: * reduce bypass_threshold from (chunk_size / sectors_per_chunk) to (1) and make it configurable. This defaults to fairness and modest performance gains out of the box. Changes since v2: * [neilb@suse.de]: kill STRIPE_PRIO_HI and preread_needed as they are not necessary, the important change was clearing STRIPE_DELAYED in add_stripe_bio and this has been moved out to make_request for the hang fix. * [neilb@suse.de]: simplify get_priority_stripe * [dan.j.williams@intel.com]: reset the bypass_count when ->hold_list is sampled empty (+11%) * [dan.j.williams@intel.com]: decrement the bypass_count at the detection of stripes being naturally promoted off of hold_list +2%. Note, resetting bypass_count instead of decrementing on these events yields +4% but that is probably too aggressive. Changes since v3: * cosmetic fixups Tested-by: James W. Laferriere <babydr@baby-dragons.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 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>
2008-02-06md: allow a maximum extent to be set for resyncingNeilBrown1-0/+10
This allows userspace to control resync/reshape progress and synchronise it with other activities, such as shared access in a SAN, or backing up critical sections during a tricky reshape. Writing a number of sectors (which must be a multiple of the chunk size if such is meaningful) causes a resync to pause when it gets to that point. 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>
2007-05-09md: allow reshape_position for md arrays to be set via sysfsNeilBrown1-28/+44
"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>
2006-10-03Fix typos in Documentation/: 'Q'-'R'Matt LaPlante1-2/+2
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'Q'-'R'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03Fix typos in Documentation/: 'N'-'P'Matt LaPlante1-2/+2
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'N'-'P'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03Fix typos in Documentation/: 'D'-'E'Matt LaPlante1-3/+3
This patch fixes typos in various Documentation txts. This patch addresses some words starting with the letters 'D'-'E'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03Fix some typos in Documentation/: 'A'Matt LaPlante1-1/+1
This patch fixes typos in various Documentation txts. This patch addresses some words starting with the letter 'A'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03[PATCH] md: fix duplicity of levels in md.txtNeilBrown1-12/+5
md.txt has two sections describing the 'level' sysfs attribute, and some of the text is out-of-date. So make just one section, and make it right. Cc: Christian Kujau <evil@g-house.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] md: new sysfs interface for setting bits in the write-intent-bitmapPaul Clements1-0/+9
Add a new sysfs interface that allows the bitmap of an array to be dirtied. The interface is write-only, and is used as follows: echo "1000" > /sys/block/md2/md/bitmap (dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk bitmaps of array md2) echo "1000-2000" > /sys/block/md1/md/bitmap (dirty the bits for chunks 1000-2000 in md1's bitmap) This is useful, for example, in cluster environments where you may need to combine two disjoint bitmaps into one (following a server failure, after a secondary server has taken over the array). By combining the bitmaps on the two servers, a full resync can be avoided (This was discussed on the list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: Allow the write_mostly flag to be set via sysfsNeilBrown1-0/+5
It appears in /sys/mdX/md/dev-YYY/state and can be set or cleared by writing 'writemostly' or '-writemostly' respectively. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: Allow resync_start to be set and queried via sysfsNeilBrown1-0/+6
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: Allow raid 'layout' to be read and set via sysfsNeilBrown1-0/+5
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: Allow rdev state to be set via sysfsNeilBrown1-0/+3
The md/dev-XXX/state file can now be written: "faulty" simulates an error on the device "remove" removes the device from the array (if it is not busy) Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: Set/get state of array via sysfsNeilBrown1-0/+39
This allows the state of an md/array to be directly controlled via sysfs and adds the ability to stop and array without tearing it down. Array states/settings: clear No devices, no size, no level Equivalent to STOP_ARRAY ioctl inactive May have some settings, but array is not active all IO results in error When written, doesn't tear down array, but just stops it suspended (not supported yet) All IO requests will block. The array can be reconfigured. Writing this, if accepted, will block until array is quiescent readonly no resync can happen. no superblocks get written. write requests fail read-auto like readonly, but behaves like 'clean' on a write request. clean - no pending writes, but otherwise active. When written to inactive array, starts without resync If a write request arrives then if metadata is known, mark 'dirty' and switch to 'active'. if not known, block and switch to write-pending If written to an active array that has pending writes, then fails. active fully active: IO and resync can be happening. When written to inactive array, starts with resync write-pending (not supported yet) clean, but writes are blocked waiting for 'active' to be written. active-idle like active, but no writes have been seen for a while (100msec). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] md: increase the delay before marking metadata clean, and make it ↵NeilBrown1-0/+9
configurable When a md array has been idle (no writes) for 20msecs it is marked as 'clean'. This delay turns out to be too short for some real workloads. So increase it to 200msec (the time to update the metadata should be a tiny fraction of that) and make it sysfs-configurable. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow sync-speed to be controlled per-deviceNeilBrown1-0/+22
Also export current (average) speed and status in sysfs. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: support adding new devices to md arrays via sysfsNeilBrown1-0/+8
Writing major:minor to md/new_dev will bind that device to the array. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow available size of component devices to be set via sysfsNeilBrown1-0/+7
Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: export rdev->data_offset via sysfsNeilBrown1-0/+6
Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: expose device slot information via sysfsNeilBrown1-0/+8
This the role that a device has in an array can be viewed and set. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow md/raid_disks to be settableNeilBrown1-0/+3
If array is active, try to reshape, else just set the value. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: count corrected read errors per driveNeilBrown1-0/+11
Store this total in superblock (As appropriate), and make it available to userspace via sysfs. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow array level to be set textually via sysfsNeilBrown1-0/+8
Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: expose md metadata format in sysfsNeilBrown1-0/+6
Allow it to be set to a particular version, or 'none'. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow md array component size to be accessed and set via sysfsNeilBrown1-0/+9
Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow chunk_size to be settable through sysfsNeilBrown1-0/+8
... only before array is started of course. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] md: allow dirty raid[456] arrays to be started at bootNeilBrown1-0/+24
See patch to md.txt for more details Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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