mdadm --detail output: 2 questions
Hi all,
I made a raid5 array with command
mdadm -Cv /dev/md3 -n5 -x1 -l5 /dev/sd{a,b,c,d,e,f}1
It took me a while to undertand that while syncing a raid5 mdadm --detail marks as failed the spare disk + 1. Is that correct? here the output before it was finished and afterwords. The last one really was produced by mdadm 1.5, the first one by mdadm 1.2, since
####### mdadm --detail /dev/md3 mdadm v. 1.2 - while syncing #############
root@nas-macpro root # mdadm --detail /dev/md3/dev/md3:
Version : 00.90.00
Creation Time : Thu Apr 22 12:55:22 2004
Raid Level : raid5
Array Size : 980317696 (934.90 GiB 1003.85 GB)
Device Size : 245079424 (233.73 GiB 250.96 GB) Raid Devices : 5
Total Devices : 7
Preferred Minor : 3
Persistence : Superblock is persistent
Update Time : Thu Apr 22 12:55:22 2004
State : dirty, no-errors
Active Devices : 4
Working Devices : 6
Failed Devices : 1
Spare Devices : 2
Layout : left-symmetric
Chunk Size : 128K
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/scsi/host0/bus0/target0/lun0/part1
1 8 17 1 active sync /dev/scsi/host0/bus0/target1/lun0/part1
2 8 33 2 active sync /dev/scsi/host0/bus0/target2/lun0/part1
3 8 49 3 active sync /dev/scsi/host1/bus0/target0/lun0/part1
4 0 0 4 faulty
5 8 81 5 /dev/scsi/host1/bus0/target2/lun0/part1
6 8 65 6 /dev/scsi/host1/bus0/target1/lun0/part1
UUID : 74aad38c:ee99c8cd:e8df8d30:c2d07f91
Events : 0.1
####### mdadm --detail /dev/md3 mdadm v. 1.5 -sync finished #############
root@nas-macpro root # mdadm --detail /dev/md3/dev/md3:
Version : 00.90.00
Creation Time : Thu Apr 22 12:55:22 2004
Raid Level : raid5
Array Size : 980317696 (934.90 GiB 1003.85 GB)
Device Size : 245079424 (233.73 GiB 250.96 GB) Raid Devices : 5
Total Devices : 7
Preferred Minor : 3
Persistence : Superblock is persistent
Update Time : Thu Apr 22 17:22:01 2004
State : dirty, no-errors
Active Devices : 5
Working Devices : 6
Failed Devices : 1
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 128K
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/scsi/host0/bus0/target0/lun0/part1
1 8 17 1 active sync /dev/scsi/host0/bus0/target1/lun0/part1
2 8 33 2 active sync /dev/scsi/host0/bus0/target2/lun0/part1
3 8 49 3 active sync /dev/scsi/host1/bus0/target0/lun0/part1
4 8 65 4 active sync /dev/scsi/host1/bus0/target1/lun0/part1
5 8 81 5 spare /dev/scsi/host1/bus0/target2/lun0/part1
UUID : 74aad38c:ee99c8cd:e8df8d30:c2d07f91
Events : 0.2
##########################################################################
in both output I see 7 'Total devices' and 1 Failed but I don't have any failed in reality nor in the last part of the output. Am I misunderstanding the output?
Last question: what is the meaning of 'Events: 0.2' (0.1 during syncing)?
Thaks in advance
sandro
*:-)
Signature · 3 lines
Sandro Dentella *:-) e-mail: [email protected] http://www.tksql.org TkSQL Home page - My GPL work
Quoted 10 lines · On Thursday April 22, [email protected] wrote:
Hi all,
I made a raid5 array with command
mdadm -Cv /dev/md3 -n5 -x1 -l5 /dev/sd{a,b,c,d,e,f}1It took me a while to undertand that while syncing a raid5 mdadm --detail marks as failed the spare disk + 1. Is that correct? here the output before it was finished and afterwords. The last one really was produced by mdadm 1.5, the first one by mdadm 1.2, since
Yes. That is correct. Rebuilding a drive is faster than correcting all parity blocks, so mdadm prefers that approach.
Quoted 5 lines
##########################################################################
in both output I see 7 'Total devices' and 1 Failed but I don't have any failed in reality nor in the last part of the output. Am I misunderstanding the output?
No, the kernel isn't quite keeping track of things properly.
Quoted 3 lines
Last question: what is the meaning of 'Events: 0.2' (0.1 during syncing)?
Just a sequence number of superblock updates.
NeilBrown