things that can be called on if necessary; reserves.
When I put effort into something I want to keep it around. That’s why I’m paranoid about my backups.
I do all of my work in the Dropbox folder. This means the files are backed up as soon as I save them. It also gives me a limited form of version control (though if I need more I’ll use a local Git repository).
Time Machine is enabled on each Mac. Since this part of the backup has a higher delay than Dropbox, I don’t rely it on for files I’m actively working on.
CrashPlan runs on each machine (including the NAS). Since the local disks contain Time Machine archives, all the machines and their history are replicated to CrashPlan. The full Time Machine archive is safe as long as at least one copy, local or remote, is preserved. The NAS is setup in a RAID-1 array with large disks to tolerate individual hardware failures and perserve as much history as possible.
The only realistic scenario where I can lose data is if my local backups and CrashPlan fail at the same time. That said, I’m lacking a routine for testing the backups. For example, if something goes wrong with Time Machine, the bad version will still get backed up to CrashPlan.