Backup and Restore Errors

6.12 Identify backup and restore errors

Backup failures are common, but are serious problems that you must deal with immediately. I can’t stress enough the importance of backing up your data. When you experience continual failures of the backup system, you put your organization’s valuable data on the line every day the problem persists.

Backup failures can originate from a variety of causes, including hardware, software, and misconfiguration of the programs and their restore procedures.

Backup hardware

Tape backup systems are mechanical in nature and are very prone to failure, especially due to lack of periodic maintenance and cleaning.

Most backup errors are caused by media write errors, meaning that the backup application was unable to write to the tape during the operation. The tape may be faulty, or the tape mechanism may be dirty or in need of maintenance.

Cleaning the magnetic heads of your tape drive on a regular basis with a cleaning tape will reduce the number of errors.

Tape robots, sometimes called a jukebox, have special mechanical components that automatically load and eject tapes into a drive. These robots are easily prone to mechanical failure, and should be periodically serviced to maintain optimum operation.

The tapes themselves may also be faulty. A tape may be faulty, despite being used numerous times, or may be faulty straight out of the package. Whenever a backup fails due to a media tape error, remove the tape from your rotation scheme and throw it out. If you use the tape again, more than likely it will repeat the failure.

You should always set a maximum time, or specific number of backups, that a tape can be used. Tapes should be used for about one year and then removed from rotation, especially if they are reused frequently. The constant writing and rewriting of the magnetic media will slowly deteriorate it, making it more likely to fail.

Most media errors are caused by neglecting to periodically clean the tape drive heads.

Backup software

Misconfiguration and software errors may also cause your backups to fail. When you have a backup failure, your first task should be to examine your backup logs.