When was the backup last tested?

An automatic copy is of less use if important folders are missing or nobody notices that the backup has stopped. Backup needs both a well-thought-out set-up and regular checks.

Decide what you need to be able to recover

Draw up an overview of important files and systems. Work out how much new work you can afford to lose, and how long you can be without access. That gives you a better basis for deciding how often to back up and how much history you need.

Consider more than one type of incident

A NAS on the same premises can give quick access to a copy, but it can also be hit by fire or theft. An extra copy somewhere else can reduce this risk. Access and protection against deletion must also be considered, so that one incident does not affect all the copies at the same time.

Test a restore

Restore agreed files to a suitable test area and check the contents. Note what was tested and the result. A test like this is useful, but it does not prove that all systems can be restored or that a particular deadline can be met.

Decide who follows up on alerts, storage space and tests. It should be a concrete routine, not just a setting that nobody looks at again.