I have a Redhat 8.0 machine running the 2.4.18 kernel. It has Seagate Dat 9SP040-000 Rev 9070 tape drive running off a Adapec AHA 2940VW Pro SCSI card. Whenever any data bigger than 100 megs or so is written to the tape drive it hard locks the machine. The last message I see is

I can eject the tape, erase it, do anything with the mt command without any issues. Small files can be backed up without issue. I have changed tapes and gotten the same errors. I'm sure it possible the tape drive or scsi card are having problems...but i get the gut feeling this is a problem with software configuration. I have a proprietary software that will be running the backups in the long run, but even tar'ing over a file gives the lock ups. Perhaps a block size problem? I'm really not sure whats up as I don't have much experience with tape drives.

Thanks for any help!

Is it possible to turn DMA off for this device?
If not , since I have absolutely no experience with tape drives or scsi proprietary cards,
try turning on/off APIC, ACPI or other interrupt/DMA related things.

I have no idea. hdparm perhaps? When I'm at work tomorrow (where the machine is) ill dig around for things like that. Anyone else have any ideas?

yeah use hdparm or go with the safer kernel boot parameter settings for controller settings.

"safer kernel boot parameter settings for controller settings"

I dont undersand what you mean. Little n00b explination for me?

When using the hdparm command on the device (no matter what switch I use on it) I get this output

I hate to bump a topic, but I'm still trying to get this working right. Any one have any insight? Thanks guys!