RAID-5 and database servers
poweredge at antibozo.net
Thu Mar 11 16:29:21 CST 2010
On 2010-03-11 22:23, Matthew Geier wrote:
> I've had a disk fail in such a way on a SCSI array that all disks on
> that SCSI bus became unavailable simultaneously. When half the disks
> dropped of the array at the same time, it gave up and corrupted the RAID
> 5 meta data so that even after removing the offending drive, the array
> didn't recover.
In that scenario you *should* be able to recover by reconfiguring the
RAID as it originally was before the SCSI crash, and *not* initializing
the logical drives.
I have my systems all mail me a nightly report of RAID configuration in
case I ever need to do this. While I might be able to remember how I
configured RAIDs at install time, the config may change over time, e.g.
after a hot spare is brought online.
If you are using LSI-based RAID controllers, you might be able to save
the current controller config with MegaCLI using the -cfgsave option
periodically, and recover the config after a crash using -cfgrestore.
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