zfs discuss - Jul 2010 - Consequences of resilvering failure

I''m just about to start using ZFS in a RAIDZ configuration for a home
file
server (mostly holding backups), and I wasn''t clear on what happens if
data
corruption is detected while resilvering.  For example: let''s say
I''m using
RAIDZ1 and a drive fails.  I pull it and put in a new one.  While resilvering, 
ZFS detects corrupt data on one of the remaining disks.  Will the resilvering 
continue, with some files marked as containing errors, or will it simply fail?

(I found this process[1] to repair damaged data, but I wasn''t sure what
would
happen if it was detected in the middle of resilvering.)

I will of course have a backup of the pool, but I may opt for additional backup 
if the entire pool could be lost due to data corruption (as opposed to just a 
few files potentially being lost).

Thanks,
Michael

[1] http://dlc.sun.com/osol/docs/content/ZFSADMIN/gbbwl.html


      
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----- Original Message -----
> I''m just about to start using ZFS in a RAIDZ configuration for a
home
> file server (mostly holding backups), and I wasn''t clear on what
> happens if data corruption is detected while resilvering. For example:
> let''s say I''m using RAIDZ1 and a drive fails. I pull it
and put in a
> new one. While resilvering, ZFS detects corrupt data on one of the
> remaining disks. Will the resilvering continue, with some files marked
> as containing errors, or will it simply fail?
The pool will remain available, but you will have data corruption. The simple
way to avoid this, is to use a raidz2, where the chances are far lower for data
corruption.

Vennlige hilsener / Best regards

roy
--
Roy Sigurd Karlsbakk
(+47) 97542685
roy at karlsbakk.net
http://blogg.karlsbakk.net/
--
I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er
et element?rt imperativ for alle pedagoger ? unng? eksessiv anvendelse av
idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og
relevante synonymer p? norsk.

On Tue, Jul 6, 2010 at 10:05 AM, Roy Sigurd Karlsbakk <roy at
karlsbakk.net>wrote:
> The pool will remain available, but you will have data corruption. The
> simple way to avoid this, is to use a raidz2, where the chances are far
> lower for data corruption.
>
It''s also possible to replace a drive while the failed / failing drive
is
still in the system. If some of the disk still has usable data, it can be
used in the resilver.

Of course using raidz2 or raidz3 is probably easier.

-B

-- 
Brandon High : bhigh at freaks.com
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