BACKUP RECOVERY MANAGEMENT

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1 BACKUP RECOVERY MANAGEMENT Network Security Course Muhammad Salman Computer Engineering, University of Indonesia

2 Backups and Disaster Recovery Factors in choosing backup media: Amount of data Cost of media Performance Reliability Ease of offsite storage

3 Backups and Disaster Recovery Methods of file backup: Normal Differential Incremental

4 Normal Backup A normal, or full, backup copies all selected files, in their entirety. Each file is then marked as having been backed up. With normal backups, only the most recent backup is required to restore files. This speeds up and simplifies the restore process. However, because all data is backed up, a full backup takes the most amount of time.

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6 Differential Backup A differential backup copies only the files that have been changed since the last full backup. With differential backups, a full backup on the first day of the backup cycle is necessary. Only the files that are created or changed since the time of the last full backup are then saved. The differential backup process continues until another full backup is run. This reduces the amount of time required to perform the backup. When it is time to restore data, the last normal backup is restored and the latest differential backup restores all changed files since the last full backup.

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8 Incremental Backup An incremental backup differs from a differential backup on one important point. Whereas a differential backup saves files that were changed since the last full backup, an incremental backup only saves files that were created or changed since the last incremental backup. This means that if an incremental backup is run every day, the backup media would only contain files created or changed on that day. Incremental backups are the quickest backup. However, they take the longest time to restore because the last normal backup and every incremental backup since the last full backup must be restored.

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10 Backups and Disaster Recovery How to ensure successful backups: Swap media Review backup logs Trial restores Drive maintenance

11 Swap Media Many backup scenarios require daily swapping of media to maintain a history of backed up data. Data loss could occur if the tape or disk is not swapped daily. Because swapping the tapes is a manual task, it is prone to failure. Users need to use a notification method, such as calendar or task scheduling.

12 Review Back Logs Virtually all backup software produces logs. These logs report on the success of the backup or specify where it failed. Regular monitoring of backup logs allows for quick identification of any backup issues that require attention.

13 Trial Restore Even if a backup logs shows that the backup was successful, there could be other problems not indicated in the log. Periodically perform a trial restore of data to verify that the backup data is usable and that the restore procedure works.

14 Drive Maintenance Many backup systems require special hardware to perform backups. Tape backup systems use a tape backup drive to read and write to the tapes. Tape drives can become dirty from use and can lead to mechanical failure. Perform routine cleaning of the tape drive using designated cleaning tapes. Hard drive-based backup systems can benefit from an occasional defragmentation to improve the overall performance of the system.

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