Unix Backup and Recovery

You Can Find a Balance

Using a system that has no backups is like driving a car 100 miles an hour down a busy road the day after your insurance policy expires. Likewise, having a three-node, highly-available cluster for a noncritical application is like having full coverage on your 20-year-old, fifth car. Just as insurance plans have different levels of coverage and riders to cover various types of damage, different backup methodologies provide different levels of recoverability.

Don’t Go Overboard

Not all environments need up-to-the-minute data recoverability. For many environments, recovering the systems up to last night’s backups is acceptable. For some environments, recovering the system even up to last week or month is OK. Spending thousands of dollars and hundreds of hours implementing the greatest backup solution in the world is a waste—if you don’t need that level of coverage. This usually is not the problem for most sites; on the contrary, most sites don’t spend nearly enough money or effort on their backup and recovery system. In other cases, however, money sometimes is wasted on an unnecessarily elaborate system.

Recoverability requirements also vary from machine to machine within the same company. The amount of work that would be lost, or the possibility of adversely affecting a customer, may determine these requirements. For example, it may be considered acceptable for an employee or two to lose a day’s work spent on a few word processing documents. That is, unless it ...