Hi Trent,
if the problem is only on process of read/write on a disk, i think like Ralf, that could be a I/O problem.
You can check this with the comand:
#iostat 5 5 (interval - count)
and you can specify what device you want to ckeck too, in order to know if it's a problem with a specific device.
# iostat dsk12 dsk4 (example..)
have you checked the /var/adm/messages for an error or warning message?
REgards,
Santibon