failed raid5 after ide cable malfunction.

failed raid5 after ide cable malfunction.

[stephan sperber]

Hello everybody!
I have a little trouble in getting the raid5 up and running again.
What has happened so far:
1. Booting the System
2. Ide cable had some troubles so 2 disks went "mad" during boot and raid
couldn't get assembled.
(/dev/sda4 /dev/sdb2)
3. I forced poweroff because system wasn't responsible due to ATA connection
problems.
4. after reboot the raid5 got up again, were clean, but attempted a resync.
5. during the resync the cable had troubles again, so those 2 devices were
marked as spare.
6. i forced a poweroff again and reseated the cable.
7. I booted again but now all devices of the raid were marked as spare.

Is there a possibility to get the raid active without dataloss?

Here some infos:
cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]
[raid10] 
md1 : inactive sdc2[2](S) sdb2[1](S) sda4[0](S)
      709140864 blocks
       
unused devices: <none>

mdadm --detail /dev/md1
mdadm: md device /dev/md1 does not appear to be active.

Thx in advance
Stephan

Re: failed raid5 after ide cable malfunction.

[Justin Piszcz]

On Wed, 7 Jan 2009, stephan sperber wrote:

> Hello everybody!
> I have a little trouble in getting the raid5 up and running again.
> What has happened so far:
> 1. Booting the System
> 2. Ide cable had some troubles so 2 disks went "mad" during boot and raid
> couldn't get assembled.
> (/dev/sda4 /dev/sdb2)
> 3. I forced poweroff because system wasn't responsible due to ATA connection
> problems.
> 4. after reboot the raid5 got up again, were clean, but attempted a resync.
> 5. during the resync the cable had troubles again, so those 2 devices were
> marked as spare.
> 6. i forced a poweroff again and reseated the cable.
> 7. I booted again but now all devices of the raid were marked as spare.
>
> Is there a possibility to get the raid active without dataloss?
>
> Here some infos:
> cat /proc/mdstat
> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]
> [raid10]
> md1 : inactive sdc2[2](S) sdb2[1](S) sda4[0](S)
>      709140864 blocks
>
> unused devices: <none>
>
> mdadm --detail /dev/md1
> mdadm: md device /dev/md1 does not appear to be active.
>
> Thx in advance
> Stephan
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Example (use your disks obviously):

# mdadm --assemble --force /dev/md3 /dev/sd[c-l]1

If that does not work, you can use Neil's advice from another thread:

> Your only option at this stage is to re-create the array with the best
> devices.  Create it will one device missing so that it won't try a
> resync.
> e.g.

>  mdadm -C /dev/md0 -l5 -n5 /dev/hde1 /dev/hdg1 /dev/hdi1 missing /dev/sda1

You would want -C /dev/md1 -l5 -n3 and then specify only two of the disks
with one "missing"

See if this does it for you?

Justin.

RE: failed raid5 after ide cable malfunction.

[stephan sperber]

# mdadm --assemble --force /dev/md3 /dev/sd[c-l]1
This hint did it :) Thank you for your great help!

Have a nice day.

Stephan

-----Original Message-----
From: linux-raid-owner@vger.kernel.org
[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Justin Piszcz
Sent: Wednesday, January 07, 2009 7:19 PM
To: stephan sperber
Cc: linux-raid@vger.kernel.org
Subject: Re: failed raid5 after ide cable malfunction.



On Wed, 7 Jan 2009, stephan sperber wrote:

> Hello everybody!
> I have a little trouble in getting the raid5 up and running again.
> What has happened so far:
> 1. Booting the System
> 2. Ide cable had some troubles so 2 disks went "mad" during boot and raid
> couldn't get assembled.
> (/dev/sda4 /dev/sdb2)
> 3. I forced poweroff because system wasn't responsible due to ATA
connection
> problems.
> 4. after reboot the raid5 got up again, were clean, but attempted a
resync.
> 5. during the resync the cable had troubles again, so those 2 devices were
> marked as spare.
> 6. i forced a poweroff again and reseated the cable.
> 7. I booted again but now all devices of the raid were marked as spare.
>
> Is there a possibility to get the raid active without dataloss?
>
> Here some infos:
> cat /proc/mdstat
> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
[raid4]
> [raid10]
> md1 : inactive sdc2[2](S) sdb2[1](S) sda4[0](S)
>      709140864 blocks
>
> unused devices: <none>
>
> mdadm --detail /dev/md1
> mdadm: md device /dev/md1 does not appear to be active.
>
> Thx in advance
> Stephan
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Example (use your disks obviously):

# mdadm --assemble --force /dev/md3 /dev/sd[c-l]1

If that does not work, you can use Neil's advice from another thread:

> Your only option at this stage is to re-create the array with the best
> devices.  Create it will one device missing so that it won't try a
> resync.
> e.g.

>  mdadm -C /dev/md0 -l5 -n5 /dev/hde1 /dev/hdg1 /dev/hdi1 missing /dev/sda1

You would want -C /dev/md1 -l5 -n3 and then specify only two of the disks
with one "missing"

See if this does it for you?

Justin.




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