ZFS kernel panic

[Bakul Shah]

> When you don't use redundant configuration (no mirror, no raidz, no
> copies>1) then ZFS is going to panic on a write failure. It looks like
> ZFS found a bad block on your disk.

Does SUN really say this about ZFS?  Is this acceptable in a
production environment?  What if one of your mirrored disk
fails and in the "degraded" environment (before you have had
a chance to replace the bad disk) ZFS discovers that a write
fails?  Why can't it find an alternative block to write to?