The database server must be online or in quiescent mode
during an external backup.
To perform an external backup without
disk mirroring:
- To obtain an external backup, block the database server
with the onmode -c block command. The
system takes a checkpoint and suspends all update transactions. Users
can access the database server in read-only mode.
- To back up the storage spaces and administrative files,
use a copy command, such as cp, dd,
or tar on UNIX or copy on Windows, or a file-backup program.
You must back up all chunks in the storage spaces.
- To allow normal operations to resume, unblock the database
server with the onmode -c unblock command.
- Back up all the logical logs including the current log
so that checkpoint information is available for the external restore.
Important: Because external backup is not done through ontape,
you must ensure that you have a backup of the current logical log
from the time when you execute the onmode -c block command.
Without a backup of this logical-log file, the external backup is
not restorable.
- After you perform an external backup, back up the current
log. using the ontape -a command.
If you lose a disk or the whole system, you are now ready
to perform an external restore.