http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg07640.html suggests sending the event count: The event count of the devices is /dev/hda1: 0.3088065 /dev/sdb1: 0.3088063 * (out of sync) /dev/sdc1: 0.3088065 /dev/sdd1: 0.3088062 ** (dropped dead) /dev/sde1: 0.3088065 /dev/sdf1: 0.3088065 cu Jörg -------- Original-Nachricht -------- > Datum: Tue, 07 Apr 2009 16:02:25 +0200 > Von: "Jörg Habenicht" <j.habenicht@xxxxxx> > An: linux-raid@xxxxxxxxxxxxxxx > Betreff: how to restore a raid5 with 1 disk destroyed and 1 kicked out? > Hello list, hello Neil, > > I hope you may help me with this one: > > During a RAID5 synchronisation with one faulty disk my server crashed and > left my RAID in an unsynced state. I'd like to get the content from the > array back to freshen my last backup (4 months ago) and then build the array > anew. > > The array consists of 6 disks, right now 1 is dead (hw failure) and one is > "out of sync". I assume the latter is just marked out of sync without > being so.(*) > > > In http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg08909.html > and http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg06332.html you > suggested to recreate the array with --assume-clean. > In http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg08162.html > you advised not to use --assume-clean for RAID5, it may very well break. > Is it ok to use --assume-clean on a degraded array (5 out of 6, RAID5)? > > > Would it be better to recreate the array without --assume-clean? (E.g. > like "mdadm --create /dev/md0 disk1 disk2 disk3 missing disk5 disk6") > > Just out of interest: What is the difference between the two commands? > > I think /deb/sdb1 is marked "out of sync" without being so. Is > "--assume-clean" used exactly for this case? > > > Thank you in advance for any advice or help > cu > Jörg > > > > (*) > /dev/sdd1 dropped dead > /dev/sdb1 is marked 'out of sync', but I think the content on the disk is > in sync with the array > > > Now the dirty details: > > ~ # mdadm -S /dev/md0 > mdadm: stopped /dev/md0 > > ~ # mdadm --assemble --force /dev/md0 --run --verbose /dev/sdb1 > /dev/hda1 /dev/sdc1 /dev/sde1 /dev/sdf1 > mdadm: looking for devices for /dev/md0 > mdadm: /dev/sdb1 is identified as a member of /dev/md0, slot 6. > mdadm: /dev/hda1 is identified as a member of /dev/md0, slot 1. > mdadm: /dev/sdc1 is identified as a member of /dev/md0, slot 2. > mdadm: /dev/sde1 is identified as a member of /dev/md0, slot 3. > mdadm: /dev/sdf1 is identified as a member of /dev/md0, slot 5. > mdadm: no uptodate device for slot 0 of /dev/md0 > mdadm: added /dev/sdc1 to /dev/md0 as 2 > mdadm: added /dev/sde1 to /dev/md0 as 3 > mdadm: no uptodate device for slot 4 of /dev/md0 > mdadm: added /dev/sdf1 to /dev/md0 as 5 > mdadm: added /dev/sdb1 to /dev/md0 as 6 > mdadm: added /dev/hda1 to /dev/md0 as 1 > mdadm: failed to RUN_ARRAY /dev/md0: Input/output error > mdadm: Not enough devices to start the array. > > ~ # cat /proc/mdstat > Personalities : [raid6] [raid5] [raid4] [raid1] > md0 : inactive hda1[1] sdf1[5] sde1[3] sdc1[2] > 976791680 blocks > > ~ # mdadm -D /dev/md0 > /dev/md0: > Version : 00.90.03 > Creation Time : Mon Apr 3 12:35:48 2006 > Raid Level : raid5 > Used Dev Size : 244195904 (232.88 GiB 250.06 GB) > Raid Devices : 6 > Total Devices : 4 > Preferred Minor : 0 > Persistence : Superblock is persistent > > Update Time : Tue Apr 7 12:02:58 2009 > State : active, degraded, Not Started > Active Devices : 4 > Working Devices : 4 > Failed Devices : 0 > Spare Devices : 0 > > Layout : left-symmetric > Chunk Size : 64K > > UUID : b72d31b8:f6bbac3d:c1c586ef:bb458af6 > Events : 0.3088065 > > Number Major Minor RaidDevice State > 0 0 0 0 removed > 1 3 1 1 active sync /dev/hda1 > 2 8 33 2 active sync /dev/sdc1 > 3 8 65 3 active sync /dev/sde1 > 4 0 0 4 removed > 5 8 81 5 active sync /dev/sdf1 > > ~ # mdadm -IR /dev/sdb1 > mdadm: /dev/sdb1 attached to /dev/md0, not enough to start (4). > > ~ # cat /proc/mdstat > Personalities : [raid6] [raid5] [raid4] [raid1] > md0 : inactive sdb1[0] hda1[1] sdf1[5] sde1[3] sdc1[2] > 1220987584 blocks > > ~ # mdadm -D /dev/md0 > (.....) > Number Major Minor RaidDevice State > 0 8 17 0 spare rebuilding /dev/sdb1 > 1 3 1 1 active sync /dev/hda1 > 2 8 33 2 active sync /dev/sdc1 > 3 8 65 3 active sync /dev/sde1 > 4 0 0 4 removed > 5 8 81 5 active sync /dev/sdf1 > > > > I already tried > - "mdadm --assemble /dev/md0 /dev/sdb1 /dev/hda1 /dev/sdc1 /dev/sde1 > /dev/sdf1" > - "mdadm --assemble --force /dev/md0 /dev/sdb1 /dev/hda1 /dev/sdc1 > /dev/sde1 /dev/sdf1" > > > > -- > cu, > Joerg > > -- > THE full automatic planets host > :-) http://planets.unix-ag.uni-hannover.de > > > > Neu: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate + > Telefonanschluss für nur 17,95 Euro/mtl.!* > http://dslspecial.gmx.de/freedsl-surfflat/?ac=OM.AD.PD003K11308T4569a > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- cu, Joerg -- THE full automatic planets host :-) http://planets.unix-ag.uni-hannover.de Psssst! 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