[ The PC Guide | System Care Guide | Backups and Disaster Recovery | Backup Scheduling and Media Rotation Systems ]

Media Rotation Tradeoffs

The reason that there are different rotation schemes is that there are different systems, and different people who use them, and therefore different needs. The backup requirements of a home PC are very different than the server for a business. There is also a matter of media cost, which in turn depends on the type of backup being done. In general, these are the tradeoffs:

• Retention Period: Using more media sets gives you a higher retention period, protecting you against various kinds of problems better.
• Media Failure Protection: The more media you use, the less likely you will have a failure with your backup device that cripples you. You also lengthen the life of each individual backup disk or tape, if you are using that type of backup device.
• Cost: In general, using more media sets costs more money. This can be an important factor in deciding on a backup unit. A Jaz drive is fast and has random access, but ten backup media for it costs about a thousand dollars. One reason that professionals use 8mm tape drives or similar for backup is that the media cost for 8mm tapes is about 1% of that for removable drives like the Jaz.
• Restore Time: Systems that rely on incremental backups take much more time to restore in the event of a disaster.

Warning: Under no circumstances should you use only one media set when performing backups. The risks to this data set are large and the protection you are getting from your backups is going to be severely compromised by this decision. One of the most common problems with doing this is the possibility of a hard disk crash or power spike during a backup itself; if this happens you could easily lose both your system and backup at the same time. While any backup is better than none, this warning falls into the category of "if you're going to do it, you might as well do it properly".

Next: Minimum Security Rotation System

Home  -  Search  -  Topics  -  Up