ZFS secondarycache on SSD problem on r255173

[Matthew D. Fuller]

On Mon, Mar 03, 2014 at 11:17:05AM +0200 I heard the voice of
Andriy Gapon, and lo! it spake thus:
> 
> I noticed that on some of our systems we were getting a clearly
> abnormal number of l2arc checksum errors accounted in l2_cksum_bad.
> The hardware appeared to be in good health.

FWIW, I have a system here where I see similar things; after
sufficient uptime it shows an impressive number and proportion of
checksum errors (50% or more of the hits, eventually), since at least
sometime last fall.  No indication anywhere else of problems (CAM,
SMART, zpool status).

Haven't tried the patches.  It would take most of a month of seeing
nothing to have much confidence they did anything anyway; it's got >2
weeks now and only ~500 errors, so it takes a long time with this
system/workload to ramp up.  But it'd be a nice fix to have, so mark
me up as a user-vote for landing if the code makes sense to the
codesense people.


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.