Before you begin an external backup, keep the following
rules in mind:
The database server must be online or quiescent during an external
backup.
Use ontape to back up all logical logs
including the current log so that you can restore the logical logs
at the end of the external restore.
Suspend continuous logical-log backups before you block the
database server for an external backup. After the external backup
is complete, resume the continuous logical-log backup.
Wait until all ontape backup sessions
have completed before you block the database server. If any backup
sessions are active, the block command displays an error message.
Any OLTP work or queries are suspended
while the database server is blocked. They resume after the database
server is unblocked.
All critical dbspaces of the database server instance must be
backed up together simultaneously within the same command bracket
of onmode -c block ... onmode -c unblock.
Backups of different critical dbspaces done at different times cannot
be restored to a consistent system.
Important:
Because the external backup is outside the control of ontape,
you must track these backups manually. For more information, see Tracking
an External Backup.