I have a Mac Mini with OS X Mountain Lion Server installed. I've turned on Time Machine in the server app and selected an internal disk to backup clients to. On my iMac, I have turned on Time Machine and selected the backup share listed on the server. But, I recieve the following error dialog box:

Time Machine couldn’t complete the backup to “server”. Back disk is not available. I'm clearly able to connect to the server and the Shared Items > Backup folder, which the server created. I'm also made sure file permissions look right.

Any ideas?

2 Answers 2


I kept getting Backup not available so before doing a tmutil setdest I unmounted the drive and manually mounted using mount_afp, that did the trick for me.


It worked for me as posted here: http://forum.qnap.com/viewtopic.php?p=280705:

  1. Open a terminal
  2. Type in the following line:

sudo tmutil setdestination afp://TimeMachine:[email protected]/TMBackup

(where "password" is your Timemachine password and the IP address is your Time Machine IP Address. The NAS disk ipaddress TMBackup is the Time machine share)

  1. Open System Preferences
  2. Click on TimeMachine
  3. Choose select disk...
  4. Select your TimeMachine backup disk (TMBackup)

Enjoy backing-up your Mac OSX Mountain Lion.

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