[Techtalk] raid array problems

[Maria McKinley]

Thanks for the tips Cynthia. I ran out and bought a 320 GB ide drive,
which I am currently restoring the home directory to for the time being,
so that we can have a working home. Once that is restored, I am going to
start playing around with the RAID array again. I am now in contact with
the person who set it up, and he is going to do a lot of the rebuilding.
This time I am going to be there for it, and document what is done (he
is terrible at documenting, which is why I had no idea what we had). He
also suspects that two of the drives have failed, but we don't want to
do anything until we have home restored and can safely play with the
RAID array on a different machine (can't pull out the scsi card until
after the restore is done).

Are there specific recommendations you would give for setting up a RAID
array?

Thanks a bunch!

cheers,
maria

Cynthia Kiser wrote:
> OK so the computer where the RAID is mounted boots from local disk but
> has a SCSI RAID card that seems to have 1 large array - #0. The bad
> sector errors on boot seem to indicate you have a bad disk - and bad
> in a way that doesn't let the RAID cover for it. Do you have any idea
> what the RAID configuration was meant to be? Was this one big RAID 5
> or RAID 10 array? Both of those should have been robust to a single
> disk failure, so the fact you are seeing errors at the OS level makes
> me wonder if you lost 2 disks.
> 
> Poke around in the configuration utility. You should be able to
> inspect the setup without changing it. See if it will tell you what
> the configuration was and what disk or disks are showing errors. That
> will tell you what you will need in terms of replacement disks. Who
> knows, you might find it was configured with a cold spare already in
> the machine. 
> 
> However, I would also start looking to see what backups you have of
> everyone's home directories. It is possible that once you have
> replaced the bad disks, you can rebuild the array without losing
> data. But I fear that between the first problem where the disk came
> back up after reboot and your current set of problems, you have lost
> the redundency that would allow for that recovery. But post back what
> you find from the configuration and see if there is a path from where
> you are now to full home directory access that does not involve
> rebuilding your array and then restoring the data from backup.
> 
> 
> Quoting Maria McKinley <maria at shadlen.org>:
> 
>>It is a hardware array. When I boot up I can go into the adaptec raid 
>>configuration utility, and it gives me an option to use the disk 
>>utility. I am given one cnannel to select #0. Should I try it? There
>>are also options to use a SCSISelect Utility and an Array Configuration 
>>Utility.
>>
>>When I continue with boot, it tells me
>>SCSI disk error : host 1 channel 0 id 0 lun 0 return code = 1
>>I/O error: dev 08:00, sector 6
>>read_callback: read failed, status = 5
>>
>>It repeats this same error, with the only thing changing the sector 
>>(sector 6,0,2,4 all have error)
>>
>>Then it says
>>unable to read partition table
>>fsck.ext3: No such device or address while trying to open /dev/sda1
>>Possibly non-existent or swap device?
>>/dev/hdc: clean, 181981/7340032 files, 11664506/14653918 blocks
>>
>>fsck failed. Please repair manually.
>>
>>I'm not sure that all of this is to do with the raid array, but it seems 
>>likely. It then gives me an oportunity to do maintenance or CONTROL-D to 
>>continue. Then computer boots up normally, except raid array is not mounted.
>>
>>-maria
> 
>