use your ubuntu machine as an apple server that supports Time Machine

I don’t have a Mac server. 
I wanted to use Mac’s Time Machine to backup my laptop without buying Time Capsule or manually connecting an external drive every time. 
I have an extra PC that is running Ubuntu as my file server. 

… ::searches Google:: …

oh hai, this lets me do backups automatically.  woop! 

http://www.kremalicious.com/2008/06/ubuntu-as-mac-file-server-and-time-machine-volume/