using time machine on a Sparse image

Discussion in 'Mac Apps and Mac App Store' started by BENI, Sep 1, 2011.

  1. BENI macrumors regular


    Jun 27, 2009
    Just wondering if it is possible to restrict time machines use of my Ext HD by backing up the "backups.backupdb" onto a very large (600GB) sparse disk image?

    i don't want to partition my Ext HD but i don't need months and months of backup data.

    is this possible or is there another way.

    thanks in advance :)
  2. blevins321 macrumors 68030

    Dec 24, 2010
    Winnipeg, MB
    Yeah that should work. Here are the instructions on how to do it on a remote network share. The same logic should apply (minus the network mounting bits) for a sparebundle on a local USB drive.
  3. BENI thread starter macrumors regular


    Jun 27, 2009
    great really glad! thanks for the quick reply

    i'll give it a go and post back with progress
  4. BENI thread starter macrumors regular


    Jun 27, 2009

    more searching on google and i discovered that it is widely assumed to be impossible! and when i tried it it wouldn't work. after several attempts from various angles i returned to google seeking sympathy.

    after ages i found this article:

    explaining how to use a command line:

    hdiutil create -size 1024g -fs HFS+J -volname "Time Machine Backup" /Volumes/Mimzy/Bunny_0017f202b9ec.sparsebundle

    this should of course be modified to your requirements e.g. change the path / size etc...

    i couldn't get this to work but the author also mentions a piece of software called "time tamer". (his link to this is no longer useful but you can find it here,-drobo-s,-drobopro,-drobo-b800i-support-for-lion-time-machine

    i was afraid that it would only work for drobo machines but i gave it a go and i am currently backing up to the disk image now.

    An IMPORTANT POINT!: time machine will not recognise the sparsebundle its self but if you put it on your Ext HD (at the top - not in a folder) then time machine will automatically write to it rather than the straight to the ext HD

    i am still backing up but i will post when i know whether the backup is functioning correctly

    hope this helps someone :)
  5. hobspain macrumors regular


    Mar 29, 2010

    Thanks a lot Beni!. Using TimeTamer has worked wonderfully for me. Also your IMPORTANT POINT is key, as in TimeMachine you will have to accept to use the whole disk drive and "hope" that it will not be overwritten by TimeMachine. Magically it starts using the sparseimage in the external HD automatically without touching the rest of the external HD content.

    I also want to comment -if it's of any help to other users- that TimeTamer couldn't create the sparseimage in the external drive (a NTFS formatted drive) and created the sparse image on my desktop. Nothing to worry about: I moved the sparse image file to the root directory of my external drive, mounted it and worked with no problem :)

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