ZFS - scrub lead to corruption?

[Paul Pathiakis]

From: Bob Friesenhahn <bfriesen at simple.dallas.tx.us>

To: Xin LI <delphij at gmail.com>
Cc: Paul Pathiakis <pathiaki2 at yahoo.com>; freebsd-fs at freebsd.org
Sent: Tue, January 26, 2010 11:04:39 AM
Subject: Re: ZFS - scrub lead to corruption?

On Mon, 25 Jan 2010, Xin LI wrote:

>> 16) scrub continues to over 75% (I wasn't watching for the exact #) and then *panic* level 12
> 
> Do you have console access to the server?  Try setting up a crash dump
> and see if you can obtain a backtrace?
> 
> By the way, 'zpool status -x' may give some information that is useful.

Since scrub automatically re-starts after system reboots, it should help to use 'zpool scrub -s pool' immediately after boot (assuming there is enough time to do a console login) to stop the existing scrub.  This may defer the panic enough to figure out what is going wrong.

I used to get system panics here (Solaris 10) during scrub, but it was eventually determined that a flaky fiber channel card was to blame. Two systems paniced here during 'zfs scrub' and both times it was due to problems with an adaptor card.

Bob
--
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/

Thank you, Bob.  It worked fine.  I'm up and working on the machine as I'm typing this.  The zpool status <pool> says everything's fine. (??!!)  That's a relief.  However, why did the scrub cause it to crash?  

I'd like to ask this list a serious question:

What can I do to check what is causing scrub to panic the machine?
Is there any other consistency tool that I can run on ZFS to see if something is corrupted/wrong?

As a forward action, I'm going to cvsup STABLE again and try rebuilding.  I'm about to check to see if m4 is still there but I'm worried that the /usr/bin directory is where my trouble exists and I'll be crashing again.

Please let me know.  (Bob, BTW, I just checked into OpenSolaris bootable CD it's nice, you may want to check it out - FreeBSD is still a passion due to it's BSD storied history.)

Thanks!

Paul

I'd like to ask this list