Hi all,
currently I'm completly confused about what happened to my RAID 5 array.
After a crash (don't know why) I tried to reboot and start the array, but I only get the following:
linux:/mnt/raidcmds # mdadm /dev/md0 --assemble /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 --force --verbose
mdadm: looking for devices for /dev/md0
mdadm: /dev/sdb1 is identified as a member of /dev/md/0, slot 3.
mdadm: /dev/sdc1 is identified as a member of /dev/md/0, slot 0.
mdadm: /dev/sdd1 is identified as a member of /dev/md/0, slot 1.
mdadm: /dev/sde1 is identified as a member of /dev/md/0, slot 2.
mdadm: added /dev/sdd1 to /dev/md/0 as 1
mdadm: added /dev/sde1 to /dev/md/0 as 2
mdadm: added /dev/sdb1 to /dev/md/0 as 3
mdadm: added /dev/sdc1 to /dev/md/0 as 0
mdadm: failed to RUN_ARRAY /dev/md/0: Input/output error
linux:/mnt/raidcmds #
Dmesg gives you:
md: bind<sdd1>
md: bind<sde1>
md: bind<sdb1>
md: bind<sdc1>
md: md0: raid array is not clean -- starting background reconstruction
raid5: device sdc1 operational as raid disk 0
raid5: device sdb1 operational as raid disk 3
raid5: device sde1 operational as raid disk 2
raid5: device sdd1 operational as raid disk 1
raid5: allocated 4219kB for md0
raid5: raid level 5 set md0 active with 4 out of 4 devices, algorithm 2
RAID5 conf printout:
--- rd:4 wd:4
disk 0, o:1, dev:sdc1
disk 1, o:1, dev:sdd1
disk 2, o:1, dev:sde1
disk 3, o:1, dev:sdb1
md0: bitmap file is out of date, doing full recovery
md0: bitmap initialisation failed: -5
md0: failed to create bitmap (-5)
The individual komponents look like:
linux:/mnt/raidcmds # mdadm -E /dev/sdb1
/dev/sdb1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Name : 0
Creation Time : Mon Jul 28 12:24:21 2008
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 1953519728 (931.51 GiB 1000.20 GB)
Array Size : 5860558848 (2794.53 GiB 3000.61 GB)
Used Dev Size : 1953519616 (931.51 GiB 1000.20 GB)
Super Offset : 1953519984 sectors
State : clean
Device UUID : 50f883b3:4e2b85a2:4683fb8d:52843dc4
Internal Bitmap : -234 sectors from superblock
Update Time : Sun Sep 6 10:27:19 2009
Checksum : 26ec807e - correct
Events : 635952
Layout : left-symmetric
Chunk Size : 128K
Array Slot : 4 (0, 1, failed, 2, 3)
Array State : uuuU 1 failed
linux:/mnt/raidcmds # mdadm -E /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Name : 0
Creation Time : Mon Jul 28 12:24:21 2008
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 1953519728 (931.51 GiB 1000.20 GB)
Array Size : 5860558848 (2794.53 GiB 3000.61 GB)
Used Dev Size : 1953519616 (931.51 GiB 1000.20 GB)
Super Offset : 1953519984 sectors
State : clean
Device UUID : c74c2f5b:e55bdc9c:79d6d477:1a8f8073
Internal Bitmap : -234 sectors from superblock
Update Time : Sun Sep 6 10:27:19 2009
Checksum : 620b6382 - correct
Events : 635952
Layout : left-symmetric
Chunk Size : 128K
Array Slot : 0 (0, 1, failed, 2, 3)
Array State : Uuuu 1 failed
linux:/mnt/raidcmds #
linux:/mnt/raidcmds # mdadm -E /dev/sdd1
/dev/sdd1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Name : 0
Creation Time : Mon Jul 28 12:24:21 2008
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 1953519728 (931.51 GiB 1000.20 GB)
Array Size : 5860558848 (2794.53 GiB 3000.61 GB)
Used Dev Size : 1953519616 (931.51 GiB 1000.20 GB)
Super Offset : 1953519984 sectors
State : active
Device UUID : f3f8c901:1754c385:83751837:e436d87e
Internal Bitmap : -234 sectors from superblock
Update Time : Sun Sep 6 10:27:19 2009
Checksum : bc284fad - correct
Events : 635953
Layout : left-symmetric
Chunk Size : 128K
Array Slot : 1 (0, 1, failed, 2, 3)
Array State : uUuu 1 failed
linux:/mnt/raidcmds # mdadm -E /dev/sde1
/dev/sde1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Name : 0
Creation Time : Mon Jul 28 12:24:21 2008
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 1953519728 (931.51 GiB 1000.20 GB)
Array Size : 5860558848 (2794.53 GiB 3000.61 GB)
Used Dev Size : 1953519616 (931.51 GiB 1000.20 GB)
Super Offset : 1953519984 sectors
State : active
Device UUID : 6f1caf60:af57a73e:bba7287d:55bd20ee
Internal Bitmap : -234 sectors from superblock
Update Time : Sun Sep 6 10:27:19 2009
Checksum : 894a2e75 - correct
Events : 635953
Layout : left-symmetric
Chunk Size : 128K
Array Slot : 3 (0, 1, failed, 2, 3)
Array State : uuUu 1 failed
linux:/mnt/raidcmds #
Proc/mdstat tells you:
linux:/mnt/raidcmds # cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : inactive sdc1[0] sdb1[4] sde1[3] sdd1[1]
3907039232 blocks super 1.0
unused devices: <none>
linux:/mnt/raidcmds #
The array is not started looking like this:
linux:/mnt/raidcmds # mdadm -D /dev/md0
/dev/md0:
Version : 1.00
Creation Time : Mon Jul 28 12:24:21 2008
Raid Level : raid5
Used Dev Size : 976759808 (931.51 GiB 1000.20 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Sun Sep 6 10:27:19 2009
State : active, Not Started
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 128K
Name : 0
UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Events : 635952
Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
1 8 49 1 active sync /dev/sdd1
3 8 65 2 active sync /dev/sde1
4 8 17 3 active sync /dev/sdb1
linux:/mnt/raidcmds #
And finally the bitmaps looking like this:
linux:/mnt/raidcmds # mdadm -S /dev/md0
mdadm: stopped /dev/md0
linux:/mnt/raidcmds # mdadm -X /dev/sdb1
Filename : /dev/sdb1
Magic : 6d746962
Version : 4
UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Events : 635953
Events Cleared : 635952
State : Out of date
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 976759808 (931.51 GiB 1000.20 GB)
Bitmap : 953867 bits (chunks), 948224 dirty (99.4%)
linux:/mnt/raidcmds # mdadm -X /dev/sdc1
Filename : /dev/sdc1
Magic : 6d746962
Version : 4
UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Events : 635953
Events Cleared : 635952
State : Out of date
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 976759808 (931.51 GiB 1000.20 GB)
Bitmap : 953867 bits (chunks), 948224 dirty (99.4%)
linux:/mnt/raidcmds # mdadm -X /dev/sdd1
Filename : /dev/sdd1
Magic : 6d746962
Version : 4
UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Events : 635953
Events Cleared : 635952
State : Out of date
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 976759808 (931.51 GiB 1000.20 GB)
Bitmap : 953867 bits (chunks), 948224 dirty (99.4%)
linux:/mnt/raidcmds # mdadm -X /dev/sde1
Filename : /dev/sde1
Magic : 6d746962
Version : 4
UUID : ce761731:79e9d64a:d6f6e817:791dc8f3
Events : 635953
Events Cleared : 635952
State : Out of date
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 976759808 (931.51 GiB 1000.20 GB)
Bitmap : 953867 bits (chunks), 948224 dirty (99.4%)
linux:/mnt/raidcmds #
The array was originally build as RAID 5 with three drives. Then I added a fourth drive and issued something like mdadm --grow .... (I can not exactly remember). But as far is I know this bitmap is completly new to me. I don't think I ever defined using a bitmap for this array.
It seems to me the drives look quite good. But what is this bitmap error all about. Is it possible to simply delete the bitmap. What will happen to the data in the array?
Does this show a hardware problem with one of the disks, meaning mdadm can not write to the disk blocks, where the bitmap files need to stored (some further hardware info: the motherboard is a Asus A8N-SLI, with Athlon X2 3800, All drives are SATA and software SUSE 11.1 with uname -a:Linux linux 2.6.27.7-9-pae #1 SMP 2008-12-04 18:10:04 +0100 i686 athlon i386 GNU/Linux, mdadm --version: mdadm - v3.0-devel2 - 5th November 2008).
In the past I made some very good experience with mkraid --force but currently I do not have any /etc/raidtab file. Is it possible to use the values shown in mdadm -E or mdadm -D to recreate /etc/raidtab and to a mkraid --force?
What would you suggest as next steps?
Kind regards
Siggi
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