Hi,
I have 6 scsci disks + 1 spare in a raid5 configuration (kernel 2.2.16 etc.)
I did the following:
Raidstop /dev/md0
echo "scsi remove-single-device 0 0 1 0">/proc/scsi/scsi
Then I issued: raidstart /dev/md0 and the software is reconstructing using
the spare disk (no 6). Nice.
After rebooting the machine tells me (messages in log) that there is no disk
1 availlable and no spare disk for usage by the raid software.
I knocked the spare disk (no 6) out of the system using the echo command. It
must now run in degraded mode and after a fresh reboot all the disks should
be online.
Unfortunately, the raid software is not reconfiguring the system anymore. It
remains in degraded mode.
In the kernel messages I find the following message:
RAID5 conf printout:
--- rd:6 wd:5 fd:1
disk 0, s:0, o:1 , n:0, rd:0 us:1 dev:sda1
disk 1, s:0, o:0 , n:1, rd:1 us:1 dev:[dev 00:00]
disk 2, s:0, o:1 , n:2, rd:2 us:1 dev:sdc1
disk 3, s:0, o:1 , n:3, rd:3 us:1 dev:sdg1
disk 4, s:0, o:1 , n:4, rd:4 us:1 dev:sde1
disk 5, s:0, o:1 , n:5, rd:5 us:1 dev:sdf1
disk 6, s:0, o:0 , n:6, rd:6 us:1 dev:[dev 00:00]
disk 7, s:0, o:0, n:0, rd:0, us:0, dev:[dev 00:00]
cat /proc/scsi/aic7xxx/0 tells me that the queue depth changed from 8 to 1
exept for drive 6.
Now I want to reconstruct a complete working raid5 again.
Using a fresh reboot of the system, the software is not recognising the
correct disks as availlable and refuses them to use, even after I
repartioned them (disk 1 and 6).
I get the same raid5 conf printout.
The only way I found to get the raid5 working as it should is to issue the
mkraid command. This is not very practical since you have to backup the data
first.
Questions:
Does this also happen when one physically remove one disk (or one breaks
down) and after reconstruction, one adds a working disk to the system. Will
the system be up in a correct state with all the drives participating?
What can I do to get the raid5 up completely and not in a degraded state
without reformatting it?
What is a queue depth?
What is the meaning of the s, o, us etc in the raid5 conf printout ?
Thanks,
Nick
