WRITE_DMA errors on SATA drive under 5.3-RELEASE

Garance A Drosihn drosih at rpi.edu
Mon Feb 28 01:27:39 GMT 2005

At 3:53 PM +0100 2/27/05, Anthony Atkielski wrote:
>I've gotten two messages like the ones below today on my
>production server (5.3-RELEASE):
>... kernel: ad10: TIMEOUT - WRITE_DMA retrying (2 retries left) LBA=4848803
>... kernel: ad10: FAILURE - WRITE_DMA timed out
>What do these messages mean?  The referenced drive is one of
>two identical SATA drives on the server; it holds /tmp and /var.
>I don't recall seeing these messages before.
>Is there a way to work backwards from the LBA to the filesystem
>so that I can see which file was being referenced when this

First question: which SATA controller are you using?  And what is
the make&model of the hard drives that you are using?

Note: There have been several different threads on different mailing
lists from users having WRITE_DMA errors similar to this.  At least
some of the problem is in the code which handles disk I/O.  The
developer who works the most on that code is in the middle of a
fairly major set of improvements to it, as is described in the
thread with a subject of:

     UPDATE2: ATA mkIII first official patches - please test!

on the freebsd-current and freebsd-stable mailing list.  That major
set of improvements is still being tested, but it does solve some
ATA/SATA issues for many users.  Which issues you are running into
will depend on which SATA controller you have, and the make&model
of SATA hard-disks that you have attached to the controller.

I realize that none of that info really helps you right now, but
I just thought I would say that it may be you're not having any
hardware problems.  Or at least, not on the disk itself.  It might
be a problem with the disk-controller, or it might be fairly minor
timing-problems that come up under certain kinds of load.

Of course, it still *could* be your hard disk...  Also note that I
am not an expert on hard disks or disk I/O.  It's just that I've
suffered through many similar problems, and I know that Søren has
been working on the newer, improved code for handling ATA/SATA.

Garance Alistair Drosehn            =   gad at gilead.netel.rpi.edu
Senior Systems Programmer           or  gad at freebsd.org
Rensselaer Polytechnic Institute    or  drosih at rpi.edu

More information about the freebsd-questions mailing list