Data that is backed up in an external backup
Before you begin an external backup, block the database
server. Blocking forces a checkpoint, flushes buffers to disk, and
blocks user transactions that involve temporary tables. During the
blocking operation, users can access that database server in read-only
mode. Then you can physically back up or copy the data to another
set of disks or storage media by using operating-system or third-party
tools. When you complete the external backup, unblock the database
server so that transactions can resume. You should include all the
chunk files in each storage space and administrative files, such as onconfig,
in an external backup.
Important: To make tracking backups
easier, it is recommended that you back up all storage spaces in each
external backup.
The ontape utility treats an external backup as equivalent to a level-0 backup. You cannot perform an external backup and then use ontape to perform a level-1 backup, or vice versa because ontape does not have any record of the external backup. For more information, see Performing a cold external restore.