Fortunately, it only takes a few minutes to improve your backup strategy. Read this post, then take a few minutes to properly set up both cloud backup and local backup.
File sync is not backup
Think about what sync means: if you delete a file on one computer, it is deleted from every computer you’ve synced up, and from the cloud. So if something causes all your files on one computer to disappear, you lose them everywhere. That’s what sync is all about. File sync services sync all changes, including deletions.
Backup works differently. With backup, your files are copied to a backup drive or service, and they stay there until you delete or overwrite them. Changes you make to the files on your computer (such as deleting your /Notes folder right before trial) don’t result in changes to your past backup. You can always go restore files from your last backup.
With incremental backup — the usual method — each backup builds on the one before it, so you have a record of changes (as of the date of each backup) going back as far as your drive can store. Dedicated cloud backup services like CrashPlan (the one I use to back up my family’s computers as well as my work computers) may even store an unlimited number of incremental backups.
Using file sync services for backup
File sync services like Dropbox actually aren’t quite so strict as to immediately delete your files everywhere. Dropbox saves changes to your files going back 30 days, which means that if you discover a problem within 30 days, you can restore the file(s) you need. Since you are just as likely to realize you are missing files on day 31 as on day 29, this just isn’t enough. I often don’t discover a missing file until well beyond 30 days. (SugarSync has a similar feature; it saves the most-recent 5 versions of a file. I can’t tell what that means for deleted files, though.)
With Dropbox, you can pay for the “Packrat” option ($39/year), which stores your files forever. It’s a good deal, and it transforms Dropbox into a perfectly good cloud backup option — although a dedicated cloud backup service like CrashPlan offers several additional security layers. (SugarSync may have something similar to Dropbox’s Packrat option, but I couldn’t tell from the website.)
If you use Dropbox and don’t use any other cloud backup service, take a minute to sign up for the Packrat option (or whatever is equivalent on your file sync utility of choice). Or else sign up for Crashplan.
Always have at least 2 backups in at least 2 locations
While having cloud (or some other remote) backup is important, it isn’t enough on its own. You should also back up your files to a local drive, too. You don’t need fancy software; the built-in backup utilities for Windows and OS X are perfectly good. All you need is an external hard drive (or an extra internal hard drive) to hold your backed-up files. Set your backup to run daily.