aic78xx SCB paging

[Derek Seaman]

As I"ve mentioned before on this list I'm building a Linux system with 6
DDS-2 DAT drives so that I can make a tape duplicator system. 

My experimental system consists of 6 HP C1599A DDS-2 tape drives, a 2940U,
and a ST34572N HD. The final system will have a second 2940AU dedicated to
the tape drives.

Using kernel 2.1.87 the system works fine if I only do three 'dd' commands
at once. The SCSI LED is constantly on (as expected). However, when I start
the fourth dd, tape activity _drastically_ decreases and the SCSI LED is
mostly off. The same behavior is seen with 2.0.33.

After some experimenting, I found that turning OFF SCB paging corrects the
problem in all kernels I've tried. 

Has anyone else experienced this problem? Is this a 'feature' or a bug? 


Derek L. Seaman, Engineer
SPAWAR System Center, San Diego
Tactical Cryptologic Systems, D7213
dseaman at spawar.navy.mil
Ph: (619) 553-6795
Fx: (619) 553-1133


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