OS is hung .(swap_pager: indefinite wait buffer)

[T.shiina]

OS is hung .(Adaptec 5045 RAID5)

Operating system is hung.(FreeNAS-8.3.0BETA3)
Messages are kept displayed on the Display.
　swap_pager: indefinite wait buffer

Power OFF/ON after the recovery, error log below have been printed to dmesg.
　aac0: COMMAND 0xffffff80003c6770 (TYPE 502) TIMEOUT AFTER 122 SECONDS
　aac0: WARNING! Controller is no longer running! code= 0xbc060100
　swap_pager: indefinite wait buffer: bufobj: 0, blkno: 12934, size: 24576

What should I do for relapse prevention is to?

 

[T.shiina]

Did the following things.
Has since passed 1 month, the same event is not occurring.

1. Check the backplane cable > no problem
2. adaptec driver upgrade > Driver: 2.4 - 1 (18284)
like do not support FreeBSD8.3 is aacraid_freebsd_b18668, aacraid_freebsd_b18284 is installed.

aacraid_freebsd_b18668-> readme.txt
-FreeBSD Drivers
o FreeBSD 7.4, 8.2
aacraid_freebsd_b18284-> readme.txt
-FreeBSD Drivers
o FreeBSD 7.3, 8.x

Also confirmed in these notices. Have reseated several times during boot, reboot also hang did not.
-aacraid_freebsd_b18284-> readme.txt
4.15 Failed Arrays under FreeBSD 8
If an array fails under FreeBSD 8 (including pulling a drive
from the array), the firmware may crash causing the system
to hang or reboot automatically