Deleting From Time Machine Backup - Empty Time Machine Trash

Discussion in 'Mac Apps and Mac App Store' started by NewMacUser20009, Mar 25, 2015.

  1. NewMacUser20009 Suspended

    Nov 15, 2011
    I have used a USB drive connected to my iMac for several years to store my time machine backup. My wife is switching from an old windows computer to a new MacBook Air, and I plan to backup her new MacBook to the same drive.

    I have connected the drive to our Airport Extreme, and partitioned it so that there is a dedicated space for her backups. Everything is working properly, however I would like to remove some old files from my backup so that I can allocate more space for her backups.

    My backup takes up 2.5 TB, largely because of movies I have ripped and stored in my iTunes collection. To free up space, I went into Time Machine and chose the option to delete all backups of the iTunes movies folder, and also to exclude that folder from future backups. After entering my credentials and verifying the folder had been removed, I checked to see if there was any more free space available. Excluding this folder only freed up a roughly 25 GB of space. I was expecting 1 TB or more.

    My question is do I need to empty the Time Machine trash (if that exists) or perform some similar operation to reclaim this space?
  2. AppleNewton macrumors 68000


    Apr 3, 2007
    1 Finite Place
    I'd be wary of going from using the drive directly connected to the mac then using it on the airport, as they back-up a little different as noted here in the How To

    but thats really the only way to delete backups, they'll be completely removed from the history and if most of the files were the same chances are they're no repeats of the same file more or less symbolic links to the same file that hasn't change, hence why it wasn't a massive change storage
  3. NewMacUser20009 thread starter Suspended

    Nov 15, 2011
    @AppleNewton The folder I deleted had multiple versions over time as I added and removed movies. My process is I rip a movie and import it into my iTunes library. I also save a copy of each movie to a different USB drive to keep an archive. After watching the movie, I delete it from iTunes to free up space on my internal drive. Again, I saved a copy to a different USB drive so that I didn't totally loose the content when it was removed from iTunes. The USB drive that contains my watched movies contains roughly 1 TB of movie files. My assumption is all of these would have been backed up by time machine at some point when they were saved in my iTunes movie folder and subsequently removed. When I removed all instances of the iTunes movies folder, I expected to free up space roughly equaling the amount of movies saved on the other USB drive (roughly 1 TB of movies total) since all of these files would have been included in one instance of that folder's backup.

    Since the space freed up didn't even come close, I'm wondering if there is a secondary procedure to purge the files that have been selected for deletion, or if like a disk image the space allocated to the time machine backup needs to be manually altered down.
  4. cruisin, Mar 25, 2015
    Last edited: Mar 25, 2015

    cruisin macrumors 6502a


    Apr 1, 2014
    I believe Time Machine removes old backups as the free space becomes low to make room for newer files. If your film folder is sufficiently old, the films may have already been partially deleted. Since you marked that folder for exclusion and didn't get the space back that’s what likely happened. Time Machine keeps only the newest files, everything else is fair game for deletion.

    There is a (very) small chance that something is corrupted, and you would need to delete all the backups and start fresh. This would definitely clear up the issues but would take 4 hours or so over a wire, more for wireless.

    Also, are you measuring the space in base 10 or base 2? Hard drives are advertised in base 10 but are sometimes shown as base 2 and you loose about 7% making your 3 TB drive a 2.8 TB drive. The newer Macs use base 10 but I don't know how far back the change goes.

    Formatting the drive for use will cause a bit of space loss as well, but not much.

    Basically, you need a 2nd drive for the 2nd device or you need to delete more old backups.
  5. glenthompson macrumors 68000


    Apr 27, 2011
    Since disk drives are very cheap these days, you are better off getting a new drive to use with the Airport. As mentioned, remote backups are stored in a sparse bundle file on the drive while local drives are stored in standard folders. Also consider that drives attached to an Airport are not supported for Time Machine, only the Time Capsule. It may work but then it may fail when you need it most.

    As an alternative, consider putting a large drive on the Airport that holds all your shared media like movies and music. They are then accessible to both of you. Sue a couple of smaller drive locally attached to perform Time Machine backups. Finally, consider some type of off-site backup.
  6. NewMacUser20009 thread starter Suspended

    Nov 15, 2011
    Thanks for the suggestions. I ended up formatting the drive and creating three partitions: one for my TimeMachine backup, another for my wife's, and a 3rd for free space to restrict the size of my backups. I will expand the backups into the free space in the future if needed, but I don't want to run into the issue of a bloated backup again.

    @crusin, you are correct, TimeMachine does remove old backups to free up space when it hits the limit of space allocated to it, however the space originally allocated for the backup was 3tb, and it was only taking up 2.5tb, so it never got to the point that it needed to remove old files. The reason I wanted to reduce the size of my backup was to allocate space for my wife's backups (I just purchased a MacBook Air for her), and I was having trouble finding a way to shrink my already bloated TimeMachine Backup.

    @glenthompson, I agree drives are cheap, and ultimately I'm going to invest in an NAS enclosure, but at this time I would rather use the hardware I already have. I have read conflicting reports about if drives connected via Airport are supported for TimeMachine. From what I gathered it sounds like they didn't use to be, but in the last year Apple has relaxed their position on it. I fully agree with your suggestion for off-site backup. I have used Cashplan for offsite backup for the past 4 years, so in the event my house burns down I won't loose all of my data. As for using a 2nd drive for my wife's time machine backup - having it connected to the network is key. I don't think my wife would consistently connect a USB drive and perform a backup. It is only going to happen if it is connected over the network and running automatically in the background.

    Thank you all again for your assistance. -Frank
  7. lostgear macrumors member

    Nov 9, 2010
    Try Hdiutil compact spares bundle shell command. That may find significant space in your backup.


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