I have two Windows Server 2003 servers that connect to a Promise Technology UltraTrak RM4000 array via an Adaptec SCSI Card 39160 controller. One of these servers acts as a Microsoft Exchange Server server, and the other is a file server for user directories. Recently, I've started seeing the following errors in my event log:

•The device, \Device\Scsi\adpu160m1, is not ready for access yet.
•The driver detected a controller error on \Device\Harddisk0.

I haven't changed anything on the Windows 2003 servers. Do you know what's causing these errors?

I've seen similar problems occur with the Promise UltraTrak RM8000 array. I have limited experience with the RM4000, but it's likely similar to the RM8000. I resolved this problem on the RM8000 by dropping the SCSI transfer rate from 160MB to 80MB. I also changed the cache from write-back to write-through. After I made this change, the event log errors disappeared, and the server stopped hanging. (You didn't mention server hangs, but they were a problem on my server.)

According to Promise, this problem seems to be common on the RM series arrays. Promise also said that it doesn't technically support Ultra High Density to 68-pin highdensity cables, although that setup works fine on my server.

I've also started using LSI Logic controllers instead of Adaptec controllers. So far, I've experienced fewer problems with them.