Hello,
I've never done it but according to some old documentation I have, vxdump will request a second volume when the first one completes. It would appear you can use the -n option in your vxdump command to get the system to display a message requesting you load the second tape in the drive when it reaches the end of the first tape. Your backup will then complete over the two volumes.
Extract from the documentation below explaining in more detail:
vxdump(1M)
Operator interaction
vxdump requires operator intervention for any of the following conditions:
- end of tape
- end of dump
- tape-write error
- tape-open error
- disk-read error (if errors exceed threshold of 32)
In addition to alerting all operators implied by the
-n option,
vxdump interacts with the control terminal operator by posing questions requiring
yes or
no answers when it can no longer proceed or if something is grossly wrong.
Since making a full dump involves considerable time and effort,
vxdump establishes a checkpoint at the start of each tape volume. If, for any reason, writing that volume fails,
vxdump will, with operator permission, restart from the checkpoint after the old tape has been rewound and removed and a new tape has been mounted.
Hope this helps.
