VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Using VERITAS NetBackup to Back Up and Restore Oracle Disk Manager Files Prerelease 8 September 2005, 8:55am
264 VERITAS Storage Foundation for Oracle Administrator’s Guide
Using VERITAS NetBackup to Back Up and Restore Oracle Disk
Manager Files
Oracle allocates Oracle Disk Manager files with contiguous extent layouts for good database
performance. When you back up your database using VERITAS NetBackup, extent attributes are
backed up automatically. When you restore database files they are allocated using these extent
attributes. If you are using Oracle RMAN's conventional backup method with any backup software,
datafiles are also restored with the proper extent layouts.
If you are not using NetBackup or you are using RMAN's “proxy copy” backup method with a
backup software other than NetBackup, the extent attributes may not be backed up. To ensure the
restored datafiles have proper extent layouts, preallocate the lost datafiles using the odmmkfile
command. This command preallocates contiguous space for files prior to restoring them. Refer to
the odmmkfile(1M) manual page for more information.
Example
To preallocate an Oracle datafile with size 100 M, assuming the Oracle database block size is 8K
use the odmmkfile command and enter:
$ /opt/VRTS/bin/odmmakefile -h 8k -s 100m filename