It appears that raidhotadd doesn't always trigger a resync under 2.6.18.
Starting with a broken raid1 mirror:
root@LS10:~# mdadm --misc --query --detail /dev/md1
/dev/md1:
Version : 00.90.03
Creation Time : Thu Apr 6 13:39:04 2006
Raid Level : raid1
Array Size : 4112576 (3.92 GiB 4.21 GB)
Device Size : 4112576 (3.92 GiB 4.21 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Thu Sep 28 13:52:41 2006
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 3061bb72:5fc9adb4:9468c10f:cf1d0085
Events : 0.48
Number Major Minor RaidDevice State
0 3 2 0 active sync /dev/hda2
1 0 0 1 removed
root@LS10:~# dd bs=32256 </dev/zero >/dev/hdc2
root@LS10:~# raidhotadd /dev/md1 /dev/hdc2
root@LS10:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5]
[raid4] [multipath]
md1 : active raid1 hdc2[1] hda2[0]
4112576 blocks [2/2] [UU]
unused devices: <none>
Notice that the status immediately changed to up without any
indication of recync activity.
root@LS10:~# raidsetfaulty /dev/md1 /dev/hdc2
root@LS10:~# raidhotremove /dev/md1 /dev/hdc2
Now, we add the device using mdadm and see that the sync is in progress:
root@LS10:~# mdadm /dev/md1 -a /dev/hdc2
mdadm: re-added /dev/hdc2
root@LS10:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5]
[raid4] [multipath]
md1 : active raid1 hdc2[1] hda2[0]
4112576 blocks [2/1] [U_]
[=>...................] recovery = 6.4% (266624/4112576)
finish=0.9min speed=66656K/sec
unused devices: <none>
root@LS10:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5]
[raid4] [multipath]
md1 : active raid1 hdc2[1] hda2[0]
4112576 blocks [2/1] [U_]
[==>..................] recovery = 11.5% (476352/4112576)
finish=1.0min speed=59544K/sec
unused devices: <none>
... and in a minute it finished syncing.
It doesn't work that way on 2.6.17.13; where either raidhotadd or
mdadm -a trigger a resync.
-
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
