Essential System Administration, 3rd Edition

Planning for Disasters and Everyday Needs

Developing an effective backup strategy is an ongoing process. You usually inherit something when you take over an existing system and start out doing the same thing you’ve always done when you get a new system. This may work for a while, but I’ve seen companies try to retain their centralized, hordes-of-operators-based backup policies after they switched from a computer room full of mainframes to a building full of workstations. Such an attempt is ultimately as comical as it is heroic, but it all too often ends up only in despair, with no viable policy ever replacing the outdated one. The time to develop a good backup strategy is right now, starting from however you are approaching things at the moment.

Basically, backups are insurance. They represent time expended in an effort to prevent future losses. The time required for any backup strategy must be weighed against the decrease in productivity, schedule slippage, and so on if the files are needed but are not available. The overall requirement of any backup plan is that it be able to restore the entire system—or group of systems—within an acceptable amount of time in the event of a large-scale failure. At the same time, a backup plan should not sacrifice too much in the way of convenience, either in what it takes to get the backup done or how easy it is to restore one or two files when a user deletes them accidentally. The approaches one might take when considering only disaster recovery ...