This may indicate a hardware failure with one of your disk drive or SCSI controller.
As per Adaptec: "This file should be used if you have installed service pack 3 under Windows 2000 and have begun to experience time out errors or reduction in performance on your RAID array". See the link to Adaptec ASK Answer ID: 9426 for the file and additional details.
In calling Adaptec about this error after Windows 2000 SP4 was installed on our Windows 2000 Advanced Server, they recommended me to install an updated driver for their raid cards. After installing this updated driver, the event messages went away.
This event is common to many controllers. See event id 9 from adpu160m.
Happens every 15 minutes on my Exchange computer. The card is an Adaptec 3210S. Initial call to Adaptec said it was an informational message and to ignore it. Rebooting does not seem to fix the issue.