Mac OS X 10.7, Time Machine & ReadyNAS NV+

First posted on the 6th August, 2011 – IT
Last modified on the 1st November, 2013, at 12:18 pm

Time machine is wonderful, and has saved my bacon numerous times. As an early adopter of Time Machine, Mac OS 10.4 and a ReadyNas NV+ the not-so-simple setup procedure was followed. All was well through Mac OS X 10.6 Snow Lepoard using this combination of a custom share and sparse images of fixed maximum size. The advantage of this was that I could back up multiple macs to the same share on my NAS and limite their avalable space, and thus backup histories, using custom sparseimages. After a while Netgear implemented full support for Time Machine within the firmware and released this simple implementation. This method, however is limited to 2TB in total size and previous disk images would need to be migrated to the new share.

Then along came Mac OS X to 10.7 Lion and it’s updated AFP file sharing protocol. Obviously this broke AFP access to the NAS and also killed Time Machine, which only runs over AFP. The guys at Netgrear have been busy and have now implemented the updated version of Netatalk, the open source AFP library into their firmware (2.1.8 for the NV+) so now Lion users can mount AFP shares and use Time Machine, if you are using the supported method that is! After a bit of digging I came acrosse this article which made everything clear and looking at my console indeed I did have the following message:


System Preferences: /Volumes/backup is not supported as a Time Machine destination because kTMLockStealingSupported fsctl not implemented.

So I have two options to get Time Machine back up and running and thus allow me to update all my computers:

  • Update to the supported method of hosting Time Machine backups on the NAS and limit myself to 2TB of backups
  • Manually configure Netatalk to bless my current share for Time Machine use.
  • I think I will go for options two, especially as I also found this and so I can resize my sparse images as needed.

    So quickly SSH into the NAS as root (having enabled root access) and look at the netatalk config file using:

    cat /etc/netatalk/AppleVolumes.default

    All thats needed is to add the magic Time Machine option to the share in question by editing the netatalk config file using the joys of vi to the following:

    "/backup" "backup" cnidscheme:dbd options:tm

    In vi this is achieved by doing the following: open file in vi, locate cursor, change to insert mode by pressing I, type the text to be inserted, end insert mode by pressing escape and finally exit with saving by typing :x.

    To enable the change the Netatalk config needs to be reloaded which can either be achieved by a reboot or by :
    /etc/init.d/netatalk force-reload