Limiting the size of Time Machine backups

Discussion in 'Mac Accessories' started by macizcool, Oct 11, 2013.

  1. macizcool macrumors member

    Feb 4, 2010
    I hope this isn't an overly-asked question. After searching, I have found that many people have a Time Machine partition, so I'm guessing that's the only way to limit the size of a backup.

    I'm getting ready to help a friend setup Time Machine, as I believe it will be an easier solution for regular backups. However, I personally stopped using Time Machine a long time ago, in favor of ChronoSync, due to the lack of options offered by Time Machine. It just seems to keep backing up indefinitely, until the drive is full, and has no settings to delete outdated backup.
  2. MacUser2525 macrumors 68000


    Mar 17, 2007
    It deletes the oldest backups automatically when the volume/disk you are backing up to becomes full.
  3. macizcool thread starter macrumors member

    Feb 4, 2010
    So the only way to prevent the backups from using the entire disk is to partition?
  4. flynz4 macrumors 68040

    Aug 9, 2009
    Portland, OR
    Just curious,

    I am constantly amazed at the thought of wanting to limit backups. HDDs are essentially free... my latest look had them at about $40/TB in larger sizes (2-4TB).

    What is the point?

  5. MacUser2525 macrumors 68000


    Mar 17, 2007
    Pretty much at least that is what I always do make a partition on the backup disk the size I want to give to time machine. Now if you wanted you can still use some of the space on an entire drive dedicated to time machine, I have done this in the past when moving stuff around and was in need of some extra space to put the files being moved.
  6. dinkyrdj macrumors newbie

    Sep 1, 2013
    As for the constant backup, install TimeMachineEditor. It's a free program that allows you to schedule when time machine runs. I use it on all my macs and it works great!
  7. macizcool thread starter macrumors member

    Feb 4, 2010
    I suppose you're right, but I don't need 2TB of computer backups from my laptop. Plus, it's hard enough convincing a layperson to have an external drive with a backup of their computer... Asking them to have two external hard drives because Time Machine doesn't have a setting to limit the size is a stretch.
  8. MCAsan macrumors 601


    Jul 9, 2012
    Given that disks are dirt cheap, especially compared to a Mac, why not let Time Machine have an entire drive?
  9. ColdCase macrumors 68030

    Feb 10, 2008
    In my POV, its simpler to just partition the disk and be done with it. TM takes care of sizing automatically. You may not want your layperson tinkering around with time machine or any other backup solution preferences anyway.
  10. macizcool thread starter macrumors member

    Feb 4, 2010
    I'll have to ask my "layperson" friend :p if she's okay with backups taking over her entire drive. If not, I'll partition it for her. I just think Time Machine would be a good, automatic way for her to backup.
  11. FreakinEurekan macrumors 68040


    Sep 8, 2011
    Eureka Springs, Arkansas
    It's totally automatic. Time Machine saves hourly backups for 24 hours - daily backups for a month - and weekly backups for as long as the drive will allow. It automatically prunes the oldest weeklies. It doesn't matter if the disk gets full or not.

    I can understand (not necessarily agree with) partitioning a drive so that it can back up two separate machines, give it a certain amount per machine. But that's a rare need.
  12. murri macrumors newbie


    Nov 13, 2014
    It looks like it is possible to limit the size of time machine backups via the MaxSize key in:


    Attached Files:

  13. stormychel macrumors newbie

    Dec 26, 2014
    sudo defaults write /Library/Preferences/ MaxSize 768000

    will set a maximum backup size of 750GB (750x1024=768000)

  14. poiihy macrumors 68020


    Aug 22, 2014

    Very useful, thanks! :D
  15. Brian33 macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    Very interesting! This is new to me. I'm guessing you two are running Yosemite? I'm still on 10.8.5 Mountain Lion, and my does not currently have a "MaxSize" key, and my PreferencesVersion is "2", not "4". Perhaps this a new TM feature in Yosemite?
  16. umbilical macrumors 6502a

    May 3, 2008
    FL, USA
    that is not true (on mavericks I dont know in yosemite) I stop using time machine because I was sick of see how time machine DONT delete automatically older backups when the disk is full, so Im not on yosemite, now is fixed? Im good with time machine BUT!!! again the problem is that dont delete older backups, I need delete manually?

    I use CCC (carbon copy cloner) but if time machine delete older backup on yosemite maybe I back to time machine.

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