So this is a point of debate that probably deserves being brought to the
floor (probably for the umpteenth time, but indulge me). I've heard from
several people that I'd consider "experts" that once per year scrubbing is
sufficient, once per quarter is _possibly_ excessive, and once a week is
downright overkill. Since scrub thrashes your disk, I'd like to avoid it if
at all possible.
My opinion is that it depends on the data. If it's all data at rest, ZFS
can't correct bit-rot if it's not read out on a regular interval.
My biggest question on this? How often does bit-rot occur on media that
isn't read or written to excessively, but just spinning most of the day and
only has 10-20GB physically read from the spindles daily? We all know as
data ages, it gets accessed less and less frequently. At what point should
you be scrubbing that "old" data every few weeks to make sure a bit or two
FYI - I personally scrub once per month. Probably overkill for my data, but
I'm paranoid like that.
How often do you normally run a scrub, before this happened? It's
possible they were accumulating for a while but went undetected for
lack of read attempts to the disk. Scrub more often!
zfs-discuss mailing list