So now that the "why" (Part 1) and "what" (Part 2) of data backup have been covered, we come to the "when." When should you backup your data? How many backup sets should you keep on hand and for how long? Can you (or should you) backup everything on your network or can you pick and choose? All of these are excellent questions and the focus of this final article. First let's cover the most frequently used data backup styles.
A full backup is just what the name implies. It backs up your entire system; everything on the hard drive to include drivers, application settings, profile information, etc. A full back up is a great way to "baseline" your recovery process. Depending on your type of business, you may require large amounts of storage for the data you acquire. If this is the case, it would inefficient (and potentially costly) to schedule regular full backups.
INCREMENTAL & DIFFERENTIAL
These two backup types are similar in concept but slightly different in execution. An incremental backup will backup anything that has changed since the last full backup. This includes files that have changed multiple times since the last full backup. A differential backup also backs up anything that has changed since the last full backup but only backs up the latest version of that file. This usually means that differential backups are somewhat smaller in size than incremental but both are significantly smaller than a full backup.
The combination of these backup styles can be very effective. The question still remains, how often (when) should you backup your data? Only you can answer that question. It simply depends on how crucial the data is to your business' successful operation. To give you an idea, let me provide you with a simple example. If your business only requires customer data be backed up on a weekly basis, the following method would be more than efficient:
- Schedule a full backup to run on the last day of each month.
- Schedule an incremental backup to run each Friday night.
This would ensure that should you experience a server failure for example, you could revert to your full backup for drivers and applications (as well as older customer data) and the latest incremental backup could be used to restore the most recent server configuration changes as well as crucial customer data.
For a small business, using a single set of backup tapes - or something like an ioSafe - would probably be the most cost effective way to manage this type of backup schedule. Changing the order of the tapes is a good way to get equal usage out of the tapes so that one does not wear out sooner than the rest of the set. For example, don't always use the same tape for the full backup. Switch it up every other month or however often you feel necessary to make the most out of tape lifespan. Use this series as a baseline to help you build your backup plan and then adjust according to your needs and business growth.