NW6.0-SP5 + NSS5C

During a backup-to-disk-operation (Veritas Backupexec 9.2
latest build) the server got stuck (no abend) with volumes
SYS and IVM (containing the data) offline, volume BAK
remained online (containing the b2d-data). SYS and IVM
consist of two scsi-disks each mirrored at an Adaptec
29160-controller. BAK attached to the same controller
consists of two scsi-disks as raid0.

I had to restart the server and during reboot again received
messages about devices deactivated and other errors. The
steps taken to get the server online again are added to the
attached error log.

Because I wanted to attach a actual config.txt I ran LOAD
CONFIG, which wrote config.txt, but also gave me messages
with "CONFIG Adapter object id is invalid".

Now the server is up again, everything is remirrored and
feels smooth again, but I am a little bit concerned about
this failure.

My biggest problem is, if this failure might result from
software (BackupExec?), from a misconfiguration (myself?) or
hardware (Seagate or/and Adaptec?). Is it possible from the
given information to make a guess?