I'm using Time Machine with my Ubuntu machine since it has more disk attached to it. Here is what I had to do to get this working with Time Machine. For this, you'll need some sort of external hard drive for temporary use for configuration
1) Install Netatalk
2) Setup a share, name it something appropriate for your backup use
3) Connect your external HD, name it identically
4) Start your Time Machine backup. You don't have to let it the backup complete, we just need two files from this backup. One is a file entitled .<yourMacAddress>, and the other ".com.apple.timemachine.supported". Copy these files over to your AFP volume
5) Make sure these files appear in your AFP volume:
Code:
cd /Volumes/<yourVolume>
ls -al
6) Mount your AFP volume. It should appear listed in /Volumes with the same name as your external drive volume (if your external drive is mounted simultaneously, it may have a "-1" attached to the end of the file name. If this is the case, unmount both so that all you have in /Volumes is your AFP volume as titled in step 2 and 3
7) Your disk should appear in the Time Machine preferences pain now, and it should show you when the next backup will be. To invoke a backup now, right click on your Time Machine icon in the dock, and click "backup now"
8) A .sparsebundle disk image will be created on your network volume containing your backup