Backing up blobspaces

You can back up blobspaces in a database that uses transaction logging.

Before you begin

Before you back up a new blobspace, make sure that the log file that recorded the creation of the blobspace is no longer the current log file. You can run the onstat -l command to verify the logical-log status.

About this task

When users update or delete simple large objects in blobspaces, the blobpages are not freed for reuse until the log file that contains the delete records is freed. To free the log file, you must back it up.

Important: If you perform a warm restore of a blobspace without backing up the logical logs after updating or deleting data in it, that blobspace might not be restorable.

Procedure

To back up blobspaces:
  1. Verify the logical-log status by running the onstat -l or xctl onstat -l command.
  2. Switch to the next log file by running the onmode -l command.
  3. Back up the logical logs:
    • If the blobspace is online, run the onbar -b -l -c command.
    • If the blobspace is offline, run the onbar -b -l -O or onbar -b -O command. If this backup is successful, ON-Bar returns 178.
  4. Back up the blobspaces by running the onbar -b or onbar -b -w command.