trace for zfs panic mounting fs after crash with RC2

[Gerrit Kühn]

On Fri, 06 Nov 2009 17:02:23 -0600 "James R. Van Artsdalen"
<james-freebsd-fs2 at jrv.org> wrote about Re: trace for zfs panic mounting
fs after crash with RC2:

JRVA> How the ZIL got corrupted - if it did - is a harder question.  What
JRVA> kind of hard disk is this, and how is it connected to the system?
JRVA> Was there any redundancy (mirror, raidz)?

I have been thinking about this for some time now. I have almost the same
controller (low-profile version, different bios, but otherwise identical)
in use without these problems.
Can the 2.5" disks cause any problems? The problematic system is the only
one I have with the small drives. Maybe they somehow "lie" to the system
about the data actually being written? I remember that a long time ago
(about 10 years?) FreeBSD people suggested to turn off the write cache of
disk drives to prevent data losses. I see that the sysctl hw.ata.wc is
still there. Do people here think that this is worth giving a try? Are
there any recent experiences concerning the performance-wise impact on zfs
when turning off wc?


cu
  Gerrit