What you will learn from this tip: Three steps to maximizing the productivity of your backup systems, quickly and on the cheap. Need a downloadable copy? Go here.
How to stretch backup windows on a budget
1. Analyze this!
Start by taking a long, hard look at what it is you're backing up. In a lot of enterprises, the answer is "everything." Most of the time, that's the wrong answer, especially if your backup window is closing in on you.
Divide the data from your applications and then classify your data both according to how often it changes and how important it is to your business. Applications seldom change, so they only need be backed up infrequently. Some data is archival and seldom changes. It can also be backed up infrequently. Some things, like .tmp files, don't need to be backed up at all. Business-critical data, on the other hand, must be scrupulously protected. You'll probably find that in backups, as in so much else, the 80-20 rule applies. That is, 20% of your storage needs complete backup at frequent intervals and 80% of it can be eliminated.
2. Arrange for backup.
Ideally, you want to store your data with regard to backup classes. In other words, all the critical data goes into one logical device, the stuff that never needs to be backed up goes into another logical device, applications go in their own logical devices and so on. This makes it easy to back up data by category. You can do complete device backups, instead of the slower file-by-file backup.
This isn't always possible for performance reasons, but it is worth approximating as closely as you can.
3. Use delta backups intelligently.
If you only back up the data that has changed during the backup period, you wind up with much smaller backups. Eventually, you'll have to back up the entire category of data, but when exactly that occurs depends on the importance of the data and how frequently it changes. For example, you might only need to back up your applications when you make major patches or upgrades.
For more information:
Tip: Do you still need to do full backups?
Tip: Shorten your backup window
Webcast: Backup School
About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
This was first published in January 2005