ad8: TIMEOUT - WRITE_DMA errors UFS 7.0-RC1

[Jeremy Chadwick]

On Sun, Mar 09, 2008 at 12:50:49AM +0100, Eilko Bos wrote:
> >From the keyboard of Michael Haro, written on Sun, Jan 27, 2008 at 12:01:03AM -0800:
> > > Can anyone else using 7.0 who hasn't already (especially those using ZFS)
> > > check his/her /var/log/messages for disk TIMEOUTs or other disk error
> > > messages?  If this is widespread, I think the chances re slim that it is a
> > > hardware problem in every case.
> > 
> > I've had this problem with Hitachi sata drives using a promise sata controller.
> 
> I am using 2 160Gb Maxtor disks in geom_mirror. With 6.3 it runs fine. I 
> upgraded to 7.0-RELEASE and after install problems started. Disk TIMEOUTs
> freezed the box as soon as I initiated a lot of disk activity (e.g. make
> buildworld of building a kernel).
> 
> I 'downgraded' the box to 6.3 again (had to rebuild the mirror because it was
> touched by a newer gmirror) and now the problems have gone again. I have the
> strong impression it is not hardware bot rather 7.0-RELEASE related.
> Actually I want to get rid of the box at home (want to carry it to a datacenter)
> but if it can be helpfull I am willing to have it for another week or two at
> home to upgrade/downgrade/etc. with it.


You should consider posting the SMART stats for both /dev/ad0 and
/dev/ad1 (because you didn't disclose which disk is showing problems; I
assume ad0 though).  You can get these by installing
ports/sysutils/smartmontools and using "smartctl -a ad0" (same for ad1).

This can help narrow down the problem.  Confirming it's *not* a disk
issue is helpful.

More importantly: if the problem is easily reproducable for you under
RELENG_7, you should contact Scott Long, who has offered to help track
this problem down.

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |