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path: root/drivers/md/dm-raid.c
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* dm: remove map_infoMikulas Patocka2012-12-211-2/+2
| | | | | | | | This patch removes map_info from bio-based device mapper targets. map_info is still used for request-based targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: round region_size to power of twoJonathan Brassow2012-12-211-1/+3
| | | | | | | | | | | | If the user does not supply a bitmap region_size to the dm raid target, a reasonable size is computed automatically. If this is not a power of 2, the md code will report an error later. This patch catches the problem early and rounds the region_size to the next power of two. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* DM RAID: Fix for "sync" directive ineffectivenessJonathan Brassow2012-10-111-0/+13
| | | | | | | | | | | | | | | | | There are two table arguments that can be given to a DM RAID target that control whether the array is forced to (re)synchronize or skip initialization: "sync" and "nosync". When "sync" is given, we set mddev->recovery_cp to 0 in order to cause the device to resynchronize. This is insufficient if there is a bitmap in use, because the array will simply look at the bitmap and see that there is no recovery necessary. The fix is to skip over the loading of the superblocks when "sync" is given, causing new superblocks to be written that will force the array to go through initialization (i.e. synchronization). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Fix comparison of index and quantity for "rebuild" parameterJonathan Brassow2012-10-111-1/+1
| | | | | | | | | | | | DM RAID: Fix comparison of index and quantity for "rebuild" parameter The "rebuild" parameter takes an index argument that starts counting from zero. The conditional used to validate the index was using '>' rather than '>=', leaving the door open for an index value that would be 1 too large. Reported-by: Neil Brown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Add rebuild capability for RAID10Jonathan Brassow2012-10-111-1/+33
| | | | | | | | | | | DM RAID: Add code to validate replacement slots for RAID10 arrays RAID10 can handle 'copies - 1' failures for each mirror group. This code ensures the user has provided a valid array - one whose devices specified for rebuild do not exceed the amount of redundancy available. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Move 'rebuild' checking code to its own functionJonathan Brassow2012-10-111-25/+50
| | | | | | | | | | | | DM RAID: Move chunk of code to it's own function The code that checks whether device replacements/rebuilds are possible given a specific RAID type is moved to it's own function. It will further expand when the code to check RAID10 is added. A separate function makes it easier to read. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'for-next' of git://neil.brown.name/mdLinus Torvalds2012-08-011-5/+90
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * DM RAID: Add support for MD RAID10Jonathan Brassow2012-08-011-5/+90
| | | | | | | | | | | | | | Support the MD RAID10 personality through dm-raid.c Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | dm thin: commit before gathering statusAlasdair G Kergon2012-07-271-1/+1
|/ | | | | | | | | | | | | | | | Commit outstanding metadata before returning the status for a dm thin pool so that the numbers reported are as up-to-date as possible. The commit is not performed if the device is suspended or if the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target through a new 'status_flags' parameter in the target's dm_status_fn. The userspace dmsetup tool will support the --noflush flag with the 'dmsetup status' and 'dmsetup wait' commands from version 1.02.76 onwards. Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: move sectors_per_dev calculationJonathan E Brassow2012-07-271-9/+9
| | | | | | | | | | In preparation for RAID10 inclusion in dm-raid, we move the sectors_per_dev calculation later in the device creation process. This is because we won't know up-front how many stripes vs how many mirrors there are which will change the calculation. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: restructure parse_raid_paramsJonathan E Brassow2012-07-271-5/+20
| | | | | | | | | In preparation for RAID10 addition to dm-raid, we change an 'if' conditional to a 'switch' conditional to make it easier to see what is being checked for each RAID type. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: support non power of two target max_io_lenMike Snitzer2012-07-271-6/+5
| | | | | | | | | | | | | Remove the restriction that limits a target's specified maximum incoming I/O size to be a power of 2. Rename this setting from 'split_io' to the less-ambiguous 'max_io_len'. Change it from sector_t to uint32_t, which is plenty big enough, and introduce a wrapper function dm_set_target_max_io_len() to set it. Use sector_div() to process it now that it is not necessarily a power of 2. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* DM RAID: Use md_error() in place of simply setting Faulty bitJonathan Brassow2012-05-221-1/+1
| | | | | | | | | | | When encountering an error while reading the superblock, call md_error. We are currently setting the 'Faulty' bit on one of the array devices when an error is encountered while reading the superblock of a dm-raid array. We should be calling md_error(), as it handles the error more completely. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Record and handle missing devicesJonathan Brassow2012-05-221-4/+7
| | | | | | | | | | | | | | | Missing dm-raid devices should be recorded in the superblock When specifying the devices that compose a DM RAID array, it is possible to denote failed or missing devices with '-'s. When this occurs, we must record this in the superblock. We do this by checking if the array position's data device is missing and then forcing MD to record the superblock by setting 'MD_CHANGE_DEVS' in 'raid_resume'. If we do not cause the superblock to be rewritten by the resume function, it is possible for a stale superblock to be written by an out-going in-active table (during 'raid_dtr'). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Set recovery flags on resumeJonathan Brassow2012-05-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Properly initialize MD recovery flags when resuming device-mapper devices. When a device-mapper device is suspended, all I/O must stop. This is done by calling 'md_stop_writes' and 'mddev_suspend'. These calls in-turn manipulate the recovery flags - including setting 'MD_RECOVERY_FROZEN'. The DM device may have been suspended while recovery was not yet complete, so the process needs to pick-up where it left off. Since 'mddev_resume' does not unset 'MD_RECOVERY_FROZEN' and set 'MD_RECOVERY_NEEDED', we must do it ourselves. 'MD_RECOVERY_NEEDED' can safely be set in 'mddev_resume', but 'MD_RECOVERY_FROZEN' must be set outside of 'mddev_resume' due to how MD handles RAID reshaping. (e.g. It is possible for a user to delay reshaping a RAID5->RAID6 by purposefully setting 'MD_RECOVERY_FROZEN'. Clearing it in 'mddev_resume' would override the desired behavior.) Because 'mddev_resume' already unconditionally calls 'md_wakeup_thread(mddev->thread)' there is no need to make this call from 'raid_resume' since it calls 'mddev_resume'. Also clean up where level_store calls mddev_resume() - it current duplicates some of the funcitons of that call. - NB Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md: dm-raid should call helper function to clear rdev.NeilBrown2012-05-221-4/+1
| | | | | | | | | | | dm-raid currently open-codes the freeing of some members of and rdev. It is more maintainable to have it call common code from md.c which does this for all call-sites. So remove free_disk_sb to md_rdev_clear, export it, and use it in dm-raid.c Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Use safe version of rdev_for_eachJonathan Brassow2012-04-241-2/+2
| | | | | | | | | | Fix segfault caused by using rdev_for_each instead of rdev_for_each_safe Commit dafb20fa34320a472deb7442f25a0c086e0feb33 mistakenly replaced a safe iterator with an unsafe one when making some macro changes. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* dm raid: handle failed devices during start upJonathan E Brassow2012-03-281-2/+51
| | | | | | | | | | | | | | | The dm-raid code currently fails to create a RAID array if any of the superblocks cannot be read. This was an oversight as there is already code to handle this case if the values ('- -') were provided for the failed array position. With this patch, if a superblock cannot be read, the array position's fields are initialized as though '- -' was set in the table. That is, the device is failed and the position should not be used, but if there is sufficient redundancy, the array should still be activated. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* md: tidy up rdev_for_each usage.NeilBrown2012-03-191-8/+8
| | | | | | | | | | | | | | | | | | | md.h has an 'rdev_for_each()' macro for iterating the rdevs in an mddev. However it uses the 'safe' version of list_for_each_entry, and so requires the extra variable, but doesn't include 'safe' in the name, which is useful documentation. Consequently some places use this safe version without needing it, and many use an explicity list_for_each entry. So: - rename rdev_for_each to rdev_for_each_safe - create a new rdev_for_each which uses the plain list_for_each_entry, - use the 'safe' version only where needed, and convert all other list_for_each_entry calls to use rdev_for_each. Signed-off-by: NeilBrown <neilb@suse.de>
* dm raid: fix flush supportJonathan E Brassow2012-03-071-0/+1
| | | | | | | | | | | | | | Fix dm-raid flush support. Both md and dm have support for flush, but the dm-raid target forgot to set the flag to indicate that flushes should be passed on. (Important for data integrity e.g. with writeback cache enabled.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: set MD_CHANGE_DEVS when rebuildingJonathan E Brassow2012-03-071-6/+10
| | | | | | | | | | | | | | | | | | The 'rebuild' parameter is used to rebuild individual devices in an array (e.g. resynchronize a RAID1 device or recalculate a parity device in higher RAID). The MD_CHANGE_DEVS flag must be set when this parameter is given in order to write out the superblocks and make the change take immediate effect. The code that handles new devices in super_load already sets MD_CHANGE_DEVS and 'FirstUse'. (The 'FirstUse' flag was being set as a special case for rebuilds in super_init_validation.) Add a condition for rebuilds in super_load to take care of both flags without the special case in 'super_init_validation'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Prevent DM RAID from loading bitmap twice.Jonathan Brassow2012-01-311-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | The life cycle of a device-mapper target is: 1) create 2) resume 3) suspend *) possibly repeat from 2 4) destroy The dm-raid target is unconditionally calling MD's bitmap_load function upon every resume. If steps 2 & 3 above are repeated, bitmap_load is called multiple times. It is only written to be called once; otherwise, it allocates new memory for the bitmap (without freeing the old) and incrementing the number of pages it thinks it has without zeroing first. This ultimately leads to access beyond allocated memory and lost memory. Simply avoiding the bitmap_load call upon resume is not sufficient. If the target was suspended while the initial recovery was only partially complete, it needs to be restarted when the target is resumed. This is why 'md_wakeup_thread' is called before issuing the 'mddev_resume'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds2011-11-061-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
| * md: Add module.h to all files using it implicitlyPaul Gortmaker2011-10-311-0/+1
| | | | | | | | | | | | | | | | A pending cleanup will mean that module.h won't be implicitly everywhere anymore. Make sure the modular drivers in md dir are actually calling out for <module.h> explicitly in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/linux-dmLinus Torvalds2011-11-021-11/+37
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/steve/linux-dm: dm: raid fix device status indicator when array initializing dm log userspace: add log device dependency dm log userspace: fix comment hyphens dm: add thin provisioning target dm: add persistent data library dm: add bufio dm: export dm get md dm table: add immutable feature dm table: add always writeable feature dm table: add singleton feature dm kcopyd: add dm_kcopyd_zero to zero an area dm: remove superfluous smp_mb dm: use local printk ratelimit dm table: propagate non rotational flag
| * dm: raid fix device status indicator when array initializingJonathan E Brassow2011-10-311-11/+37
| | | | | | | | | | | | | | | | | | | | When devices in a RAID array are not in-sync, they are supposed to be reported as such in the status output as an 'a' character, which means "alive, but not in-sync". But when the entire array is rebuilt 'A' is being used, which is incorrect. This patch corrects this to 'a'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds2011-10-261-14/+14
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://neil.brown.name/md: (34 commits) md: Fix some bugs in recovery_disabled handling. md/raid5: fix bug that could result in reads from a failed device. lib/raid6: Fix filename emitted in generated code md.c: trivial comment fix MD: Allow restarting an interrupted incremental recovery. md: clear In_sync bit on devices added to an active array. md: add proper write-congestion reporting to RAID1 and RAID10. md: rename "mdk_personality" to "md_personality" md/bitmap remove fault injection options. md/raid5: typedef removal: raid5_conf_t -> struct r5conf md/raid1: typedef removal: conf_t -> struct r1conf md/raid10: typedef removal: conf_t -> struct r10conf md/raid0: typedef removal: raid0_conf_t -> struct r0conf md/multipath: typedef removal: multipath_conf_t -> struct mpconf md/linear: typedef removal: linear_conf_t -> struct linear_conf md/faulty: remove typedef: conf_t -> struct faulty_conf md/linear: remove typedefs: dev_info_t -> struct dev_info md: remove typedefs: mirror_info_t -> struct mirror_info md: remove typedefs: r10bio_t -> struct r10bio and r1bio_t -> struct r1bio md: remove typedefs: mdk_thread_t -> struct md_thread ...
| * md/raid5: typedef removal: raid5_conf_t -> struct r5confNeilBrown2011-10-111-2/+2
| | | | | | | | Signed-off-by: NeilBrown <neilb@suse.de>
| * md: remove typedefs: mddev_t -> struct mddevNeilBrown2011-10-111-6/+6
| | | | | | | | | | | | Having mddev_t and 'struct mddev_s' is ugly and not preferred Signed-off-by: NeilBrown <neilb@suse.de>
| * md: removing typedefs: mdk_rdev_t -> struct md_rdevNeilBrown2011-10-111-9/+9
| | | | | | | | | | | | | | The typedefs are just annoying. 'mdk' probably refers to 'md_k.h' which used to be an include file that defined this thing. Signed-off-by: NeilBrown <neilb@suse.de>
* | dm: raid fix write_mostly arg validationJonthan Brassow2011-09-251-1/+1
|/ | | | | | | | | | | | | Fix off-by-one error in validation of write_mostly. The user-supplied value given for the 'write_mostly' argument must be an index starting at 0. The validation of the supplied argument failed to check for 'N' ('>' vs '>='), which would have caused an access beyond the end of the array. Reported-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: add md raid1 supportJonathan Brassow2011-08-021-10/+39
| | | | | | | Support the MD RAID1 personality through dm-raid. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: support metadata devicesJonathan Brassow2011-08-021-16/+403
| | | | | | | | | | | | | | | | | | | | | | Add the ability to parse and use metadata devices to dm-raid. Although not strictly required, without the metadata devices, many features of RAID are unavailable. They are used to store a superblock and bitmap. The role, or position in the array, of each device must be recorded in its superblock. This is to help with fault handling, array reshaping, and sanity checks. RAID 4/5/6 devices must be loaded in a specific order: in this way, the 'array_position' field helps validate the correctness of the mapping when it is loaded. It can be used during reshaping to identify which devices are added/removed. Fault handling is impossible without this field. For example, when a device fails it is recorded in the superblock. If this is a RAID1 device and the offending device is removed from the array, there must be a way during subsequent array assembly to determine that the failed device was the one removed. This is done by correlating the 'array_position' field and the bit-field variable 'failed_devices'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: add write_mostly parameterJonathan Brassow2011-08-021-1/+25
| | | | | | | | | | Add the write_mostly parameter to RAID1 dm-raid tables. This allows the user to set the WriteMostly flag on a RAID1 device that should normally be avoided for read I/O. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: add region_size parameterJonathan Brassow2011-08-021-3/+79
| | | | | | | | | | Allow the user to specify the region_size. Ensures that the supplied value meets md's constraints, viz. the number of regions does not exceed 2^21. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: tidy includesAlasdair G Kergon2011-08-021-1/+2
| | | | | | A dm target only needs to use include/linux dm headers. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid: cleanup parameter handlingJonathan Brassow2011-08-021-19/+23
| | | | | | | | | | | | | | | | Re-order the parameters so they are handled consistently in the same order where defined, parsed and output. Only include rebuild parameters in the STATUSTYPE_TABLE output if they were supplied in the original table line. Correct the parameter count when outputting rebuild: there are two words, not one. Use case-independent checks for keywords (as in other device-mapper targets). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* md/dm - remove remains of plug_fn callback.NeilBrown2011-04-181-8/+0
| | | | | | | Now that unplugging is done differently, the unplug_fn callback is never called, so it can be completely discarded. Signed-off-by: NeilBrown <neilb@suse.de>
* block: remove per-queue pluggingJens Axboe2011-03-101-1/+1
| | | | | | | | Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* dm: raid456 basic supportNeilBrown2011-01-131-0/+697
This patch is the skeleton for the DM target that will be the bridge from DM to MD (initially RAID456 and later RAID1). It provides a way to use device-mapper interfaces to the MD RAID456 drivers. As with all device-mapper targets, the nominal public interfaces are the constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO and STATUSTYPE_TABLE). The CTR table looks like the following: 1: <s> <l> raid \ 2: <raid_type> <#raid_params> <raid_params> \ 3: <#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN> Line 1 contains the standard first three arguments to any device-mapper target - the start, length, and target type fields. The target type in this case is "raid". Line 2 contains the arguments that define the particular raid type/personality/level, the required arguments for that raid type, and any optional arguments. Possible raid types include: raid4, raid5_la, raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc. (again, raid1 is planned for the future.) The list of required and optional parameters is the same for all the current raid types. The required parameters are positional, while the optional parameters are given as key/value pairs. The possible parameters are as follows: <chunk_size> Chunk size in sectors. [[no]sync] Force/Prevent RAID initialization [rebuild <idx>] Rebuild the drive indicated by the index [daemon_sleep <ms>] Time between bitmap daemon work to clear bits [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_write_behind <value>] See '-write-behind=' (man mdadm) [stripe_cache <sectors>] Stripe cache size for higher RAIDs Line 3 contains the list of devices that compose the array in metadata/data device pairs. If the metadata is stored separately, a '-' is given for the metadata device position. If a drive has failed or is missing at creation time, a '-' can be given for both the metadata and data drives for a given position. Examples: # RAID4 - 4 data drives, 1 parity # No metadata devices specified to hold superblock/bitmap info # Chunk size of 1MiB # (Lines separated for easy reading) 0 1960893648 raid \ raid4 1 2048 \ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 # RAID4 - 4 data drives, 1 parity (no metadata devices) # Chunk size of 1MiB, force RAID initialization, # min recovery rate at 20 kiB/sec/disk 0 1960893648 raid \ raid4 4 2048 min_recovery_rate 20 sync\ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 Performing a 'dmsetup table' should display the CTR table used to construct the mapping (with possible reordering of optional parameters). Performing a 'dmsetup status' will yield information on the state and health of the array. The output is as follows: 1: <s> <l> raid \ 2: <raid_type> <#devices> <1 health char for each dev> <resync_ratio> Line 1 is standard DM output. Line 2 is best shown by example: 0 1960893648 raid raid4 5 AAAAA 2/490221568 Here we can see the RAID type is raid4, there are 5 devices - all of which are 'A'live, and the array is 2/490221568 complete with recovery. Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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