Which Driver Should I Use?

A Tape or Media Changer Driver should not be loaded when using ARCserve. ARCserve sends all commands directly to the SCSI Port provided by the SCSI or Fibre controller driver. A driver for a tape drive and/or a library usually causes problem when they are left loaded.

In the Windows Device Manager the device has to be disabled and should be shown as either crossed out or as unknown. In either case the driver will not be loaded. If the device is not disabled, Windows 2000 will automatically reload the driver on startup.

When the driver is loaded it will often show up in the Tape Engine debug log, tape.log.

Mark claimed changer device as unclaimed!!!
Mark claimed changer device as unclaimed AGAIN !!!

This happens because the OS tape device or media changer driver has claimed the device, and the Tape Engine needs to release and then take control of the device. The compatibility problems come up because the OS device driver continues to communicate with the device even after the ARCserve Tape Engine has claimed control of the device.

With Fibre channel since the device will be shared there will be an entry like this which is fine.
Mark tape device as shared!!!

Another common place for it to show up in the tape log is at the time of a failure with:
Mode Parameter Changed

In this case after the Tape Engine has set the device another application (such as the driver) has sent a command to the same tape device and changed its operation mode so that the command sent by the Tape Engine fails.

Some applications that are known to cause these type of problems are:
Windows OS Media Changer drivers for libraries.
Windows OS Tape Device drivers for tape drives.
Windows Removable Storage service.
HP/Compaq Management Agent - SCSI Information setting.

In the case of a SAN any system on the SAN that has access to the tape device can cause the problem and should be checked for offending applications.