freebsd stable - Nov 2005 - DMA errors

I found these messages on my computer, which is running a very recent 
RELENG_5.  Is this bad?  Does it indicate that the disk is failing?

Nov  3 07:35:48 cauchy kernel: ad4: FAILURE - READ_DMA
status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908831
Nov  3 07:35:51 cauchy kernel: ad4: FAILURE - READ_DMA
status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908863
Nov  3 07:35:55 cauchy kernel: ad4: FAILURE - READ_DMA
status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908895
Nov  3 07:35:59 cauchy kernel: ad4: FAILURE - READ_DMA
status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908895

-- 

Stephen Montgomery-Smith
stephen@math.missouri.edu
http://www.math.missouri.edu/~stephen

Stephen Montgomery-Smith wrote:
> I found these messages on my computer, which is running a very recent 
> RELENG_5. Is this bad? Does it indicate that the disk is failing?
>
> Nov 3 07:35:48 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE>
LBA=145908831
> Nov 3 07:35:51 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE>
LBA=145908863
> Nov 3 07:35:55 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE>
LBA=145908895
> Nov 3 07:35:59 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE>
LBA=145908895
>
It could be a problem with the disk, the cable, or possibly software.

Try smartctl -a /dev/ad4 as root to find out if the errors were recorded 
by the drive.

Now is a good time to do a backup, just in case :)
-- 
</jcr>