[OpenIndiana-discuss] General ZFS questions (Michelle Knight)

[Edward Ned Harvey]

> From: Gary Gendel [mailto:gary at genashor.com]
> 
> Though I generally agree with the advice that you received, I take an
> exception to the statement that checksums "always" indicate hardware or
> driver failure.  As a long-time raidz user, I can attest to the fact
> that, occasionally, changes to the zfs code have wreaked havoc with
> raidz.  In one build I tried an even number of disks works but an odd
> number produces checksum errors.
> 
> That said...  Have you run scrubs back to back?  If so, do you always
> get checksum errors and do they occur in different places? On a similar
> problem such as yours, I discovered that the scrub was introducing
> checksum errors.  I tracked it down to elevated temperatures during the
> scrub, which really pounds at the disks.  Better cooling on the disk
> tower resolved the problem.

While it's true that no software in the world is perfect and therefore there
must exist bugs in ZFS and therefore I was overstated in saying cksum errors
are always caused by hardware...

The example you gave serves the opposite purpose.  If the root cause of your
problem was elevated temperatures, that's a hardware problem.