linux software raid never assumes you want to add a disk back to an array just
cause it is working. that would be a bad thing (tm).
instead, you must tell the kernel you want to add a disk back to the array
with the raidhotadd /dev/mdX /dev/sdXX command.
allan
Art <[EMAIL PROTECTED]> said:
> 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
>
>
>
>
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