VERITAS Storage Foundation 4.1 for Oracle RAC HP Serviceguard Storage Management Suite Extracts, December 2005

Backing Up and Recovering the Database Using Storage Checkpoints

Backing Up and Recovering the Database Using Storage

Checkpoints

Storage Checkpoints can be created by specifying one of the following options: online,

offline, or instant. To create a Storage Checkpoint with the online option, the database

should be online and you must enable ARCHIVELOG mode for the database. During the

creation of the Storage Checkpoint, the tablespaces are placed in backup mode. Because it

only takes a few seconds to take a Storage Checkpoint, the extra redo logs generated while

the tablespaces are in online-backup mode are very small. You can roll back the entire

database or individual tablespaces or datafiles to an online or offline Storage Checkpoint.

After the rollback is complete, rolling the database forward is supported with online

Storage Checkpoints. For the instant option, the database should be online and it can be

running in either ARCHIVELOG or NOARCHIVELOG mode. You can only roll back the

entire database to an instant Storage Checkpoint. After the rollback is complete, you need

to perform Oracle database storage rollback instance recovery. Rolling the database

forward is not supported; that is, you cannot apply archived redo logs.

Note For best recoverability, always keep ARCHIVELOG mode enabled, regardless of

whether the database is online or offline when you create Storage Checkpoints.

Since the Storage Checkpoints record the before images of blocks that have changed, you

can use them to do a disk-based or file-system-based storage rollback to the exact time

when the Storage Checkpoint was taken. You can consider Storage Checkpoints as

backups that are online, and you can use them to roll back an entire database tablespace,

or a single database file. Rolling back to or restoring from any Storage Checkpoint is

generally very fast because only the changed data blocks need to be restored.

Note Some database changes made after a Storage Checkpoint was taken may make it

impossible to recover the database after storage rollback. For example, you may not

be able to recover the database after a successful rollback if the control files for the

database have recorded the addition or removal of datafiles. To provide recovery

options, a backup copy of the control file for the database is saved under the

$VXDBA_DBPATH

$ORACLE_SID

/checkpoint_dir/

CKPT_NAME