Using tape device groups with a changer

SCO ARCserve/Open uses the concept of grouping tape devices to give you the maximum performance in your data security efforts. Your SCO ARCserve/Open User Guide discusses several advantages to grouping drives, among them tape spanning. With standard tape drives, you would need to chain together several drives to use tape spanning.

When you use a changer, the process becomes completely automated using only one tape drive. The changer takes care of swapping tapes in and out of the drive. You can go home at night, knowing that your data will be successfully backed up, even if the process requires more than one tape.

When you are using a changer containing more than one tape drive, there are a few simple rules to remember concerning the grouping of these drives:

each tape device must be in its own group. There is no grouping together of tape drives in a changer.
each tape device ``owns'' a range of slots, or tapes. So, if your changer supports four tape drives and 120 tapes, you would probably assign each drive 30 slots.

The following figure illustrates a changer with two drives and fifty slots. The first tape drive has been assigned slots 1 through 25, and the second tape drive has been assigned slots 26 through 50: