Unix Backup and Recovery

Deciding How to Back Up

Once you’ve decided when you’re going to back up, you have to decide how you are going to back up the data. But first, look at what types of problems you are protecting yourself from.

Be Ready for Anything: Ten Types of Disasters

As stated earlier, how you want to do your restores determines how you want to do your backups. One of the questions that you must ask yourself is, “What are you going to protect yourself from?” Are the users in your environment all “power users” who use their computers intelligently and never make dumb mistakes? Would your company lose a lot of essential data if the files on your users’ PCs are accidentally deleted? If a hurricane takes out your whole company, would it be able to continue doing business? Make sure that you are aware of all the potential causes for data loss, then make sure your backup methods are prepared for all of them from which you want to protect yourself. The most exhaustive list of potential causes of data loss that I have seen was in another O’Reilly book called Practical Unix and Internet Security, by Simson Garfinkel and Gene Spafford. Their list, with my comments attached, follows:

User error

This has been, by far, the biggest percentage of restores in every environment that I have seen. “Hey, I was sklocking my flambality file, and I accidentally pressed the jankle button. Can you restore it, please?” This one is pretty easy, right? What about the common question: “Can you restore it as of about an hour ...