aacraid: Host adapter reset request. SCSI hang ?

["Omar Kilani" <omar.kilani@gmail.com>]

Hi there,

We're having issues with our Adaptec RAID controller and I was
wondering if anyone would be able to advise on how to go about
resolving them. :)

The system:

RHEL 5.1 x86_64
Kernel 2.6.18-53.1.4.el5
aacraid 1.1-5[2437]-mh4 (The default module shipped with the RHEL kernel)

The controller:

Adaptec 3405 + BBU

BIOS : 5.2-0 (12415)
Firmware : 5.2-0 (12415)
Driver : 1.1-5 (2437)
Boot Flash : 5.2-0 (12415)

The disks:

4x Seagate ST373455SS (Firmware 0002) in a RAID10

The issue:

We continually get what seem to be adapter lockups with the error:

aacraid: Host adapter abort request (3,0,0,0)
aacraid: Host adapter reset request. SCSI hang ?

The controller hangs for a while, recovers, and everything continues normally.

We've tried a replacement controller and a replacement set of disks
(we swapped out all 4 disks) to no avail.

The problem seems (?) to happen during spikes of IO -- like when the
PostgreSQL autovacuum daemon kicks in. But not always.

>From searching around LKML and Google, this seems to be a fairly
common issue, but I'm not quite clear on the cause (hardware?
software? firmware?) or the resolution.

Any help would be greatly appreciated.

Thanks!

Regards,
Omar