kernel: aac0: **Monitor** NMI ISR: NMI_SECONDARY_ATU_ERROR on Dell 2500 series server.

This is a message for the archives.

console error messages showing:

kernel: aac0: **Monitor** NMI ISR: NMI_SECONDARY_ATU_ERROR

and lots of SCSI timeouts.

To fix, start with setting

hw.pci.do_powerstate="0"

in /boot/loader.conf, and rebooting.

If this fails check your BIOS version for both the main system and the RAID 
controller (my case a Dell PERC 3/Di).

Both were factory shipped BIOSs:

Main BIOS: A01
RAID BIOS: 2.50
SMC BIOSs: 5.78/1.23

Upgrading the BIOSs to:

Main BIOS: A07
RAID BIOS: 2.80
SMC BIOSs: 5.87/1.32

Fixed the issue.  BIOS notes show that around A03/A04 there was a fix 
implemented to resolve spurious and false NMI errors.

Additional Info: Dell don't have it in the BIOS notes, update in the following 
order using floppy boot/BIOS disks:

System Management Card and Backplane.
Main (System) BIOS
**Reboot**
RAID BIOS
**Reboot**

Regards,

-- 
Matthew Sullivan
IT Security Manager
The University of Canberra

A member of the Australian Association for the Abolition of
Acronym Abuse, Regional Group Headquarters, Strategic and
Tactical Operations Planning (AAAAARGHSTOP).