Performing an external backup

About this task

The database server must be online or in quiescent mode during an external backup.

To perform an external backup without disk mirroring:

Procedure

  1. 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.
  2. 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.

  3. To allow normal operations to resume, unblock the database server with the onmode -c unblock command.
  4. 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.
  5. After you perform an external backup, back up the current log. using the ontape -a command.

Results

If you lose a disk or the whole system, you are now ready to perform an external restore.