Hi all,
Following a crash of one of our raid5 pool last week I discover that most of our servers shows the same pb. Up to now I didn't find the explanation. So if someone from the list could explain the following output and more particularly why the "failed device" after an mdadm --create with 2.4.x kernel :
dd if=/dev/zero of=part[1-5] bs=1k count=20000 losetup /dev/loop[0-5] part[0-5]
$ uname -a Linux fabtest1 2.4.27-1-686 #1 Fri Sep 3 06:28:00 UTC 2004 i686 GNU/Linux
debian kernel on this box but all the other test I did where with a vanilla kernel.
$ sudo mdadm --version
mdadm - v1.7.0 - 11 August 2004
The box is i386 with an up to date pre-sarge (debian).
(same pb with 0.7.2 on a woody box, with 1.4 woody backport and mdadm 1.8.1 doesn't start the building of the raid pool on an mdadm --create)
$ /sbin/lsmod Module Size Used by Not tainted raid5 17320 1 md 60064 1 [raid5] xor 8932 0 [raid5] loop 9112 18 input 3648 0 (autoclean) i810 62432 0 agpgart 46244 6 (autoclean) apm 9868 2 (autoclean) af_packet 13032 1 (autoclean) dm-mod 46808 0 (unused) i810_audio 24444 0 ac97_codec 13300 0 [i810_audio] soundcore 3940 2 [i810_audio] 3c59x 27152 1 rtc 6440 0 (autoclean) ext3 81068 2 (autoclean) jbd 42468 2 (autoclean) [ext3] ide-detect 288 0 (autoclean) (unused) ide-disk 16736 3 (autoclean) piix 9096 1 (autoclean) ide-core 108504 3 (autoclean) [ide-detect ide-disk piix] unix 14928 62 (autoclean)
$ sudo mdadm --zero-superblock /dev/loop[0-5]
$ sudo mdadm --create /dev/md0 --level=5 --raid-devices=6 /dev/loop[0-5] build the array correctly and gives (once the build is finished) :
$ cat /proc/mdstat
Personalities : [raid5]
read_ahead 1024 sectors
md0 : active raid5 [dev 07:05][5] [dev 07:04][4] [dev 07:03][3] [dev 07:02][2] [dev 07:01][1] [dev 07:00][0]
99520 blocks level 5, 64k chunk, algorithm 2 [6/6] [UUUUUU]
$ $ sudo mdadm -D /dev/md0
/dev/md0:
Version : 00.90.00
Creation Time : Wed Dec 1 11:39:43 2004
Raid Level : raid5
Array Size : 99520 (97.19 MiB 101.91 MB)
Device Size : 19904 (19.44 MiB 20.38 MB)
Raid Devices : 6
Total Devices : 7
Preferred Minor : 0
Persistence : Superblock is persistent Update Time : Wed Dec 1 11:40:29 2004
State : dirty
Active Devices : 6
Working Devices : 6
Failed Devices : 1
Spare Devices : 0 Layout : left-symmetric
Chunk Size : 64K UUID : 604b72e9:86d7ecd6:578bfb8c:ea071bbd
Events : 0.1 Number Major Minor RaidDevice State
0 7 0 0 active sync /dev/loop0
1 7 1 1 active sync /dev/loop1
2 7 2 2 active sync /dev/loop2
3 7 3 3 active sync /dev/loop3
4 7 4 4 active sync /dev/loop4
5 7 5 5 active sync /dev/loop5Why in hell do I get a Failed devices ? And what is the real status of the raid5 pool ?
I have this pb with raid5 pool on hd and sd hard drives with <> vanilla 2.4.x kernel. 2.6.x doesn't show this feature.
raid1 pool doesn't have this problem either.
@+,
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