The term disaster recovery is used to describe the activities that need to be done to restore the database in the event of a fire, earthquake, vandalism, or other catastrophic events. A plan for disaster recovery can include one or more of the following:
If your plan for disaster recovery is to recover the entire database on another machine, you require at least one full database backup and all the archived logs for the database. When operating your business with this consideration, you may choose to keep a standby database up-to-date by applying the logs to it as they are archived. Or, you may choose to keep the database backup and log archives in the standby site, and perform a restore/rollforward only after a disaster has occurred. (In this case, a recent database backup is clearly desirable.) With a disaster, however, it is generally not possible to recover all of the transactions up to the time of the disaster.
The usefulness of a table space backup for disaster recovery depends on the scope of the failure. Typically, disaster recovery requires that you restore the entire database, so when a major disaster occurs, a full database backup is needed on a standby site (even if you have a separate backup image of every table space, you cannot use them to recover the database). If the disaster is a damaged disk, then a table space backup (for each table space using that disk) can be used to recover. If you have lost access to a container because of a disk failure (or for any other reason), you can restore the container to a different location. For additional information, see "Redefining Table Space Containers During RESTORE".
With critical business data being stored in your database, you should plan for the possibility of a natural or man-made disaster affecting your database. Both table space backups and full database backups can have a role to play in any disaster recovery plan. The DB2 facilities available for backing up, restoring, and rolling forward data changes provide a foundation for a disaster recovery plan. You should ensure that you have tested recovery procedures in place to protect your business.
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