Backup and Restoration Flashcards
Describe the rollback and recovery backup and recovery system methodology.
A backup and recovery system method that is common to online, real-time processing. All transactions are written to a transaction log when they are processed. Periodic “snapshots” are taken of the master file. When a problem is detected, the recovery manager program starts with the snapshot of the master file and reprocesses all transactions that have occurred since the snapshot was taken.
Describe the checkpoint and restart backup and recovery system methodology.
Common to batch processing, a checkpoint is a point in data processing where the accuracy of the processing can be verified. Backups are maintained during the update process so that, if a problem is detected, it is only necessary to return to the backup at the previous checkpoint instead of returning to the beginning of transaction processing.
Define “storage area networks (SANS)”.
A method of backup that can be used to replicate data from multiple sites. Data stored on a SAN is immediately available without the need to recover it. This enables highly efficient disaster recovery.
Define “remote backup service”.
A service that provides users with an online system for backing up and storing computer files. Remote backup has several advantages over traditional backup methodologies: the task of creating and maintaining backup files is removed from the IT department’s responsibilities; the backups are maintained off site; some services can operate continuously, backing up each transaction as it occurs.
Define “mirroring”.
A method of backup consisting of the maintenance of an exact copy of a dat set to provide multiple sources of the same information. Mirrored sites are most frequently used in e-commerce for load balancing - distributing excess demand from the primary sit to the mirrored.
Define “grandfather-father-son file security control”.
A technique used to maintain redundant backup copies (three “generations”) of data files; backup files are used to recover from systems failures in which data files are damaged or destroyed.
