I use Dropbox to keep some of my files in sync and Mozy to back up my data. Recently, I noticed that Mozy was backing up files that I knew I had deleted. In fact, it referred to these files as filename […..] (deleted).pdf! I initially thought this was possibly Mozy trying to be really clever by keeping a copy of files I had deleted and backing them up, should I want them back at some point. It wasn’t… Turns out those files were actually generated by Dropbox.
Dropbox keeps a copy of deleted (and changed) files for the previous 30 days. Now, if you set Mozy to back up your Dropbox folder, it will back these files up too, because they happen to be stored in /Dropbox/.dropbox.cache/ (a hidden folder).
This wouldn’t normally be an issue but now that Mozy have phased out their unlimited price plan, you might want to limit yourself to only backing up those files that you really need. To exclude those deleted Dropbox files from your Mozy backup, all you need to do is add a rule in the preferences. Fire up System Preferences > Mozy Home. Select the Files and Folders tab and click on advanced. Under Don’t back up, hit the + and select Advanced and create this rule:
Creating a new rule in Mozy's Preferences
Update: It looks like Dropbox also have a premium option that allows you to restore deleted/changed files from more than 30 days ago. They call it Pack-Rat.