hast and zfs trim possibly causing some problems in 9.2

[Pete French]

I just had a machine fall over on my for the first time in ages - one
of a pair of machine we have running hast with zfs on top. I havent
got any concrete evidence of what made it die as yet, but I
did notice the logifles filling up with thoursands of lines like this
just prior to the crash:

serpentine-active hastd[1522]: [serp1] (primary) Remote request failed (Operation not supported): DELETE(26847744000, 1536).

so I am guessing taht is ZFS trying to send a trim command to hast, and hast
does not support it. Have disabled zfs trim now, but thought it was
worth mentioning - I would have not expected zfs to be trying to issue
a trim command to an underlying device which doesnt support it. These
machines were rock solid under 8, and the only chnage I can see with 9 is
the trim support being added.

cheers,

-pete.