Performing an external backup when chunks are not mirrored

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

To perform an external backup when chunks are not mirrored:

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 ON-Bar, 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 with the onbar -b -l -c command.

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