IDE DMA Timeouts

[hank at yerpso.net]

I'm experiencing the same issue with a brand new install, though
different hardware ... I've an Adaptec 1205 SATA controller and a pair
of Samsung 160 gig drives.

Error only occurs under load, the first time it happened the machine
locked and spontaneously rebooted and required a manual fsck of the
mirror; which completed successfully, but then rebuilt the mirror very
slowly ...

Second time, the stressor (copying a 5 gig drive image to it) the
machine held up, but got many DMA WRITE errors to ad6 ... below is the
smartctl output on that drive, but I don't see anything other than the
DMA WRITE errors, though I confess to not being really up on what
smartctl outputs ... 

lighty# ./smartctl -a /dev/ad6
smartctl version 5.33 [i386-portbld-freebsd6.0] Copyright (C) 2002-4
Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF INFORMATION SECTION ===
Device Model:     SAMSUNG HD160JJ
Serial Number:    S08HJ1MYC31118
Firmware Version: ZM100-33
User Capacity:    160,041,885,696 bytes
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   7
ATA Standard is:  ATA/ATAPI-7 T13 1532D revision 4a
Local Time is:    Mon Feb 20 08:36:15 2006 CST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

The errors don't cut and paste nicely ... but there are 35 instances of
a DMA WRITE failed, followed by 4 DMA READ fails ... 

Thoughts, comments and suggestions welcome.

Hank