zfs code - Apr 2007 - Scrubbing a zpool built on LUNs

I''m building a system with two Apple RAIDs attached. I have hardware
RAID5 configured so no RAIDZ or RAIDZ2, just a basic zpool pointing at the four
LUNs representing the four RAID controllers. For on-going maintenance, will a
zpool scrub be of any benefit? From what I''ve read with this layer of
abstration ZFS is only maintaining the metadata and not the actual data on the
drives. What''s the best practice to keep the data healthy? (scrub,
import/export, etc..) Also, where are the replicas of the metadata stored in
this configuration? Can that be backed up?

Thanks.
--
This messages posted from opensolaris.org

Mike,

Please post this sort of query to zfs-discuss (rather than zfs-code).
zfs-code is a development discussion forum.

Without any form of replication that zfs knows about (RAIDZ or mirrors),
there is no way for ZFS to fix up data errors detected in a scrub.
RAID5 LUNs just look like normal device LUNs to ZFS.  Since we always
store meta-data replicated, we *will* be able to fix meta-data errors.
A scrub may still be useful to you, however, as it will identify any
data that has checksum errors (that you can then repair by hand if
you have backup copies).

-Mark

Mike wrote:
> I''m building a system with two Apple RAIDs attached. I have
hardware RAID5 configured so no RAIDZ or RAIDZ2, just a basic zpool pointing at
the four LUNs representing the four RAID controllers. For on-going maintenance,
will a zpool scrub be of any benefit? From what I''ve read with this
layer of abstration ZFS is only maintaining the metadata and not the actual data
on the drives. What''s the best practice to keep the data healthy?
(scrub, import/export, etc..) Also, where are the replicas of the metadata
stored in this configuration? Can that be backed up?
> 
> Thanks.
> --
> This messages posted from opensolaris.org
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