More than backing up sites.
WHAT TO BACK UP
Site files Databases Mail, if you host it Configuration files A record of what is installed
THAT LAST ONE
Rebuilding a server from backups of data alone means reconstructing the configuration from memory.
Document what you installed and how it is configured.
WHERE TO STORE IT
Off the server. A backup on the same machine is lost with it.
SNAPSHOTS
Many providers offer whole-server snapshots.
Convenient, and check whether they are included or charged.
Take one before any significant change.
HOW OFTEN
Depends on how much you can afford to lose.
Daily for anything with changing data.
TESTING RESTORATION
Occasionally, actually restore something.
An untested backup is a hope.
WHAT PEOPLE DISCOVER
That the backup excluded something, or that restoration takes far longer than expected.
Better discovered deliberately.
