A little story of failed raid5 (3ware 8000 series)

[David Schwartz]

> While we are on the subject:
>
> What is the practical difference between VERIFY and REBUILD with regards
> to a RAID-5 array?

Verify should at a minimum read all the data. Ideally, it would read the
checksum blocks too to make sure they are still valid, but it might not.

Rebuild should read all the data and write out new checksum blocks. It might
also validate that it can read back the checksum.

> My Highpoint RocketRAID 2320 and 2340 cards can be scheduled to perform
> either verify or rebuild. I currently have them set to verify the arrays
> weekly. Is that reasonably often? Do I want to rebuild regularly also
> (or instead of verify)?

It really depends what these functions actually do. Ideally, verify would
read the data and the checksum and so would ensure that all data can be
read, even if one drive fails. If so, that would really be all you need to
do periodically.

DS