Database Recovery
You can use VERITAS Storage Checkpoints to implement efficient backup and recovery of databases that have been laid out on VxFS file systems. A Storage Checkpoint allows you to roll back an entire database, a tablespace, or a single database file to the time that the Storage Checkpoint was taken. Rolling back to or restoring from any Storage Checkpoint is generally very fast because only the changed data blocks need to be restored.
Storage Checkpoints can also be mounted, allowing regular file system operations to be performed or secondary databases to be started.
This chapter provides an introduction to using Storage Checkpoints for Storage Rollback of an Oracle database. For full information on how to administer the Storage Checkpoints feature for the database software that you are using, see the appropriate VERITAS Storage Foundation Database Administrator's Guide.
Note
Storage Checkpoints can only be used to restore from logical errors such as human mistakes or software faults. You cannot use them to restore files after a disk failure because all the data blocks are on the same physical device. Disk failure requires restoration of a database from a backup copy of the database files kept on a separate medium. Combining data redundancy (for example, disk mirroring) with Storage Checkpoints is recommended for highly critical data to protect against both physical media failure and logical errors.
Storage Checkpoints require space in the file systems where they are created, and the space required grows over time as copies of changed file system blocks are made. If a file system runs out of space, and there is no disk space into which the file system and any underlying volume can expand, VxFS automatically removes the oldest Storage Checkpoints if they were created with the removable attribute.
If available, it is recommended that you use the VxDBA utility to administer Storage Checkpoints when they are applied to database applications. See the VERITAS Storage Foundation Database Administrator's Guide for details.
For information on how Storage Checkpoints work, see the VERITAS File System Administrator's Guide.
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