Raw Devices and BRBACKUP/ BRRESTORE (SAP Library - Database Administration (Oracle) with SAPDBA)

Raw Devices and BRBACKUP/ BRRESTORE

The BRARCHIVE utility remains unchanged in a raw device configuration because offline redo log files must always reside in a file system.

There are some changes in the BRBACKUP and BRRESTORE programs in a raw device configuration, but these changes have no effect on the function scope of the programs. The known functionality of BRBACKUP and BRRESTORE for backing up and restoring file systems remains unchanged.

Use the dd command to access raw devices.

With dd, you can write directly from/to the raw device to/from tape (backup/restore to/from tape)

With dd, you can copy directly from/to the raw device to/from disk with file system (backup/restore to/from disk)

In case of a backup with software compression, output of the command dd is sent directly to the compress. In case of a restore with decompression, output of uncompress is sent to dd .

In case of a backup on a remote computer, output of dd is sent for example directly to remsh ( /rsh etc.). In case of a restore from a remote computer, it is sent from remsh ( /rsh etc.) to the dd command.

There are new init<DBSID>.sap parameters for defining the options for the dd command: see dd_flags and dd_in_flags.

Since the dd command does not support a dd continuation tape (in this case an I/O error is reported), a method which is similar to the cpio continuation method is not supported. This means that each individual database file residing on the raw devices must completely fit onto one tape. This restriction does not refer to the BRBACKUP continuation tape management, which means that the BRBACKUP utility can request continuation tapes if they should be necessary for backup of the next database files.