MULTIDRIVE
The MULTIDRIVE option lets you have up to four tape drives queued for unlabeled-tape BACKUP
operations. The sequence of
tape-device-names
specified in the BACKUP command determines
the order in which BACKUP writes to the tapes.
MULTIDRIVE
Guideline
If a tape drive is unavailable or off-line, or if a tape is not mounted when the BACKUP utility tries
to write to that drive, BACKUP polls the drive and displays this message:
$tape: device not ready -- beginning to poll --
The BACKUP process continues in this state until it detects that the drive is ready, with a tape
mounted.
Example
To back up a four-reel tape set using two tape drives:
1> BACKUP ($TAPE1, $TAPE2, $TAPE3, $TAPE4), *.*.*,
MULTIDRIVE
BACKUP writes to alternate tape drives until the tape set is finished. In this example, BACKUP is
set to write to tape #1 on $TAPE1, tape #2 on $TAPE2, tape #3 on $TAPE1, and tape #4 on
$TAPE2.
NEEDBOTH
The NEEDBOTH option lets you terminate a parallel BACKUP if an error occurs on one of the tapes.
NEEDBOTH
Guideline
Without the NEEDBOTH option, you cannot stop a parallel BACKUP if one of the tape operations
fails. The parallel BACKUP continues with one drive producing one copy instead of the two that
were requested.
Example
To terminate the parallel BACKUP if an error occurs on one of the tapes:
1> BACKUP ($TAPE1, $TAPE2, NEEDBOTH), *.*.*, LISTALL
BACKUP writes to alternate tape drives until the tape set is finished. In this example, BACKUP is
set to write to tape #1 on $TAPE1 and tape #2 on $TAPE2.
NOMYID
The NOMYID option disallows the use of the MYID option from RESTORE, which lets you restore
files that originally belonged to another user onto your user ID.
NOMYID
58
BACKUP
