Another quick and interesting note about Time Machine. The other day, a friend of mine set up Time Machine for use, and decided that he didn’t want to backup the /System, /Library and /Applications folders, basically just giving him backups of his /Users folder. After going into the preferences and choosing Options to add these folders to the Do Not Backup list, an interesting thing happened. After selecting the /System folder, a dialog appeared saying “Would you like to exclude other files installed with Mac OS X, such as applications and UNIX tools?” Quite conveniently, Time Machine is already set up to do what my friend wanted to do. While mucking about looking into the Begin Backup app, I noticed the file /System/Library/CoreServices/backup.bundle/Contents/Resources/System.plist , which contains a list of all of these system files that Apple refers too and will exclude from your backup.