Can I use an Ubuntu server with OS X Leopard's Time Machine?

I just bought the new version of OS X, and I want to use a drive on my Dapper Drake (Ubuntu 6.06.1 LTS) file server for Time Machine. Is there any way to do this?

I hate to be the bearer of bad news, but the answer is no:

Apple advertises that their backup utility Time Machine will work with a local drive, a USB attached drive, or even a network drive. However, all of these drives must be in some way connected (for now) to an OS X Leopard desktop or server installation. Now, I didn't just take Cupertino's word for it, I actually tried to get this to work myself. Heck, it is how I spent most of my Sunday! If you're interested, here are the steps I followed:

• I took a USB drive and formatted it for HFS+ on my MacBook Pro and then used diskUtil from Terminal.app to disable journalling (diskUtil disableJournal /Volumes/DRIVE) on the drive. Newer Linux kernels, even when compiled for HFS+ support, will not mount an HFS+ drive as read/write with journaling enabled for fear of corrupting the journal. Believe me, this can corrupt the data. Apple has stated that Time Machine will only work with journalling turned on, but I can confirm from a Leopard-to-Leopard test with the same USB drive that Time Machine works just fine with journaling turned off as well.
• I turned on Time Machine briefly in order to prepare the drive. Time Machine does not format the drive, but it does place several files and folders at the root:
  drwxr-xr-x 1 akutz akutz 6 Oct 29 00:34 .AppleDB/ drwxrwxr-x 1 akutz akutz 3 Oct 29 00:34 .AppleDesktop/ drwxrwxr-x 1 akutz akutz 4 Oct 29 00:34 .AppleDouble/ dr-xr-xr-t 1 akutz akutz 2 Oct 29 00:18 .HFS+ Private Directory Data?/ drwx------ 1 akutz akutz 3 Oct 29 00:19 .Spotlight-V100/ d-wx-wx-wt 1 akutz akutz 2 Oct 29 00:26 .Trashes/ -rw-r--r-- 1 akutz akutz 0 Oct 29 00:19 .com.apple.timemachine.supported drwx------ 1 akutz akutz 5 Oct 29 00:25 .fseventsd/ -rw-rw-r-- 1 akutz akutz 6.1K Oct 29 00:34 :2eDS_Store drwxrwxr-x 1 akutz akutz 3 Oct 29 00:34 Network Trash Folder/ drwxrwxr-x 1 akutz akutz 3 Oct 29 00:34 Temporary Items/
  

  Some forums posters are reporting that you just need the file '.com.apple.timemachine.supported' on the drive for Time Machine to work, but I have not tested that theory since it was easier to just do a real preparation with my Mac laptop.

• I took the same USB drive and plugged it into my Dapper server and then mounted it at /media/time_machine with 'mount -t hfsplus /dev/ sdf1 /media/time_machine'.
• I checked dmesg and /var/log/syslog for errors, and the drive seems to have mounted fine.
• I set the ownership on the drive to be that of my normal user account with 'chown -R akutz:akutz /media/time_machine'.
• I followed the instructions on how to install Netatalk (AFP) on Ubuntu with encrypted authentication in order to compile Netatalk with SSL support on Linux. Netatalk is the package that provides Apple File Protocol (AFP) support for Linux. Apple has stated that Time Machine will only work over AFP. Some forums posters are claiming that Time Machine works on NFS and SMB as well, but I have tried this in a Leopard-to-Leopard test and it did not work for me.
• I edited the file /etc/netatalk/AppleVolumes.default and added the line at the end '/media/time_machine "Time Machine"' so that the USB drive would be exported via AFP.
• I restarted netatalk with '/etc/init.d netatalk restart'. This takes a very long time.
• I successfully tested my connection to the USB drive via AFP from my Mac to my Linux file server. Everything seems to be in working order..
• Unfortunately, after all of this, Time Machine fails to see the drive.

I am sure some enterprising person will get this working in the near future. I have been playing with tcpdump this morning in order to see if I can figure it out myself. In the process of testing I also confirmed that Time Machine does not see drives attached to your AIrport Extreme. Another disappointment.

I guess it's time to go buy a Mac Mini.