Performing Continuous Logical-Log Backup to Disk (ON-Archive) (SAP Library - SAP Database Guide: Informix (BC-DB-INF-DBA))

Performing Continuous Logical-Log Backup to Disk (ON-Archive)

Use

This procedure describes how to perform a continuous backup of the logical log to disk with ON-Archive . In a continuous logical-log backup to disk, you:

Use a temporary storage area on disk to back up the logical log.

Copy the backed-up data to tape.

For more information about continuous logical-log backup, see Choosing Continuous Logical-Log Backup (ON-Archive).

Caution

For any of the procedures in which you use tape media, you must always make sure that the correct tape volume is mounted in the appropriate tape device. If not, the operation fails. If your logical logs are full, see Emergency Logical-Log Backup.

Prerequisites

You have defined devices for the backup to disk and the subsequent copy to tape. Refer to Defining Devices for ON-Archive Without SAP Scripts.

You have defined volume sets and volumes for the backup to disk and the subsequent copy to disk. Refer to Setting Up Volume Sets and Volumes for ON-Archive Without SAP Scripts.

You have determined the volume required for the logical-log backup and loaded it into your tape drive.

Procedure

Start continuous backup request by entering a command like the following:

$ onarchive 'BACKUP/LOGFILE/CONTINUOUS/VSET=LOGDIR'

Add the qualifier AUTOVOP for unattended mode.

Monitor save sets to find closed ones.

Copy closed save set (identified by the request ID) to your tape volume set (assuming LOGDIR was created with request ID 68):

$ onarchive 'COPY/VSET=LOGDIR/DESTINATION=LOGTAP/REQUEST=68'

Interrupt continuous backup (using Ctrl-C ).

Remove disk save set (identified by the request ID) to reclaim disk space.

Repeat the process for the next save set.

Caution

Remove the disk save set as soon as possible, but not before you have made sure that it has been safely copied offline to tape. Always use the copy command in ON-Archive ( not rm in UNIX). Do this as soon as possible, otherwise the disk might fill (in which case, you have to do an emergency backup).

Note

To find out how the backup is progressing, see Checking Logical-Log Backup Status (ON-Archive).

Result

The logical log is backed up. Therefore, you can use the logical-log backup for a restore in the event of database failure.

Make sure that you check the logical-log backup result and check the tapes. Finally, be sure to complete the logical-log backup.

See also:

Informix documentation at http://www.informix.com