I don't know what a LUN ID is. There is a jumper on the back of the tape drives where you set the SCSI ID. It is set to 3 on both the old and the new drives.

Both drives are identical, so I put the terminator from the old drive on the new drive.

If everything works as it should, can't you swap one drive with another without any configuration except making sure that the SCSI ID is the same on the new drive?

Thanks...