Russell Coker <russell@coker.com.au> writes: twb> I read this as "it didn't email me about its degraded state, so if it twb> was racked, I'd never have known until it was too late" :-) twb> [...] twb> Erm, mdadm emails me when a RAID array fails. I didn't have to write my twb> own script, because that's something everybody running an array should twb> want (more or less). If I had migrated from md to zfs, I'd have been twb> bitten by that. A mismatch of expectations, I guess.
Unfortunately mdadm doesn't necessarily email you about problems.
The original discussion was about degraded arrays, which AFAIK mdadm always tries to email me about. That appears to be about sum mismatches, which I readily agree mdadm is crap at.
Although in the case of RAID-1 a scrub seems to always report problems even when nothing is wrong so this is often an issue of a false alarm.
I noticed this too, under Ubuntu 10.04 / 2.6.32. We thought it was the swap partitions, so we removed them but the problem remained. IIRC we never resolved it, so we just ignore the mismatch warnings we get from the monthly check.