OSX Time Machine and Tonidoplug

I have a Tonidoplug (local loud storage tool) that I use to share files with family, and as a local server for backups. But one thing really bugged me when Apple changed Time Machine (OS X's primary backup tool) so that it couldn't write to samba shares because I couldn't direct my time machine backups to it. Fortunately, there's a slow but functional work-around.

First, create an HFS disk image file (note the order)

Launchpad -> Other -> Disk Utility
Name: your choice, but let's call it [macbak]
Format: Mac OS Extended (Journaled)
Encryption: You can chose any option here
Partitions: Single Partition - GUID Partition Map
Image Format: sparse bundle disk image (this is the one that makes it small but extendible)
Size: (you choose, but it should be close to the size of your Mac disk size)

Once you've created the image, copy it to the samba share on your Tonidoplug.

That done, change the following command to reflect where the share is and the disk image filename:

sudo tmutil setdestination /Volumes/macbak

Then you can open Time Machine and run a backup (note that the first backup is likely to take hours).

There you have it; it's slow, but it works.

If you need to manually mount your share later (and don't wan't to use the Disk Utility:

hdiutil mount /Volumes/Disk1Part1/macbak.sparsebundle

Then to unmount after you're done:

hdiutil unmount /Volumes/macbak