Endy's Blogomat

How to use Time Machine with a network share

There are quite a lot of useful information out there how to use a network share as destination for time machine. However I would like to add my own howto which also includes encryption oft the image.

I use this setup for a while now at home and at work. At work we use a x86 solaris box with samba and ZFS (at home i use linux and samba on ext3). If a user connects to a share a snapshot is automatically taken – if something goes wrong with a backup we can rollback. This works absolute flawless. So we have a network based backup for time machine with encryption.

Enter the following on the command-line (start Terminal):

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1
  • Now mount the image share via finder
  • Next open a terminal and enter the directory you mounted the share (e.g. /Volumes/image
  • Now open Time Machine Preferences and select the network share
  • issue a ls -la until you see a file with the endening sparsebundle and copy the name.
  • open time machine Preferences and under change disk select none.
  • ensure that in the mount directory no sparebundel exists any more and delete the file .<your mac address> – you need to execute a chmod +w in order to delete that file
  • now open disk utility from the Utility folder under Applications
  • select New image now paste the sparsebundle filename – remove .tmp inside the filename
  • set the properties to this values:


  • Encryption: select encryption – you need to provide a password and check the Store password in keychain box!
  • Create the image on your desktop – don’t worry it won’t be that big since it is growable 🙂
  • unmount the new create sparsebundle
  • Encryption: open Keychain Access under Login locate the key for the sparsebundle and copy it into the System Key chain
  • Now copy this file to your image share
  • open Time Machine Preferences and klick change disk
  • again select the image share
  • enjoy

Figthing with Time Machine on OS X (Update 2)

As mentioned earlier, time machine is not working out of the box on network shares as promised initially by Apple. After reading some Forums and blogs it looks like Apple stripped down Time Machine Configuration options in the final release. Never the less i managed with the help of the information provided in these forums and blogs to workaround this issue and enable Time Machine to backup to my netatalk AFP share on my Buffalo Linkstation. All you need is a spare USB disk. Here are the steps: 

  1.  connect the USB (or FW) drive to your mac
  2.  if time machine recognizes the drive just ignore it
  3. Rename the Drive to the name you would like to use for your backup share e.g. Backup
  4. Open Time Machine Configuration Dialog in System Preferences
  5. Now select your attached USB drive
  6. You will see the next backup Timer countdown, just cancel it by pressing the X button
  7. now connect your AFP share (Finder Cmd+K) 
  8. next open a terminal and copy two files from the USB Disk Volumen e.g.  
    cp /Volumes/Backup/.com.apple.timemachine.supported /Volumes/Backup-1/ 


    cp /Volumes/Backup/.00* /Volumes/Backup-1/
  9. now disconnect your USB Disk and unmount your AFP share
  10. Reconnect to your AFP share and select Backup Now by right klick (or Ctrl-Klick) on the TimeMachine Dock icon.
  11. Voila !  now your Backup should start.

you should see something like this: 
Time Machine creates not a simple Directory like on the attached Disk but a sparse Image which is then automatically mounted and used as the target.

Update 1:

After hours of waiting and finally a successful backup, I found out that time machine itself does not use the created backup on the network share – so you can make an automatic backup but not use the fancy interface – which is from my point of view only about 50% of what I would like to have or in other word useless 🙁 

Update 2:

hopefully this guy is right 😉