Performing Oracle Advanced Recovery - OCP: Oracle Database 12c Administrator Certified Professional - page 323

Command Purpose Example

rm rm Current.258.613087119

Removes an ASM directory
or file.

rm current*

rm -r current*

rmalias rmalias +cooked_dgroup1/11gDB/data-

file/alias_tbs_01.dbf

Removes an ASM alias.

For the purposes of the OCP exam, we are interested in the md_backup and md_restore
commands. The md_backup command provides a way to back up the ASM diskgroup meta-
data, as seen here:

md_backup -b /tmp/dgbackup070222 -g dgroup1 -g dgroup2

In this case, we are backing up the ASM metadata from two disk groups, dgroup1 and
dgroup2. This backup will be stored in the file system /tmp/dgbackup070222 .

Restoring ASM Disk Groups

Restoring ASM disk group metadata is seemingly simple, as you would just use the asmcmd
command md_restore , as seen here:

md_restore -t full -g dgroup1 -i /tmp/dgbackup070222

In this case, we are restoring the metadata for dgroup1 from the backup we took previ-
ously. However, it should be said that before attempting such an operation, it's a very good
idea to talk to Oracle Support and make sure that this step is truly required.
If you have a normal ASM configuration, it's likely that you don't really need to have
backups of the ASM metadata. However, if you have configured unique property definitions,
then a backup of the ASM disk group would be worthwhile.

Configuring and Using Oracle
Secure Backup

In the previous chapters where we discussed RMAN backup and restores, we discussed
how RMAN interfaces with tape devices. We mentioned that to send backups to tape you
use the Oracle SBT library API to communicate with the vendor table software, which then
manages the movement of the backup data to tape. This architecture works great, but there