Q: What do timeout errors from my SCSI card during a tape backup mean?

I added a Compaq 4mm SCSI DAT tape drive to my Linux system. Since that time we have not been able to get a complete/error free backup to the tape. We get SCSI timeout errors using Linux's taper program (as well as many others). The SCSI card in the system is the NCR86??s PCI SCSI

A: Your problem could be hardware or software.


You may need to upgrade the SCSI driver under Linux. If you have installed your own Linux kernel, be sure to use the ncr53c8xx SCSI driver, not the 53c7,8xx driver. They are different, and you will get SCSI timeout errors with the 53c7,8xx driver. If you have a 1.2.x or older kernel release, you probably have the 53c7,8xx driver and need to upgrade. (Kernel upgrades sometimes require other software updates, as well.)


SCSI timeout errors will result if your SCSI bus is not correctly terminated. How is your SCSI bus organized? What devices are internal or external? What devices are terminated? What devices provide termination power? Do you have any wide to narrow adapters connected? Check your SCSI bus termination.