Understanding Time Machine

Discussion in 'Apple Forum' started by simon12, Jul 7, 2015.

  1. simon12

    simon12
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    Could someone explain in brief terms to me about TM and looking into its file structure.

    Basically, I am backing up my MBA onto an ext drive with TM. If I have a look at the actual list of files in Finder I can see all the folders but some of them have a "No Entry" sign and also I can't see a date for the latest update even though I did it.

    BUT - when I enter TM the usual way, there are all the newer files in case I need them so it definitely works.

    I'm not too worried, but I am intrigued....
     
  2. simon12

    simon12
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    OK - I seem to have issues here. I am still backing up in the same way but I find that TM wants to do a complete backup of my MBAir's drive, not an incremental backup. I am obviously removing the MBA from the home frequently and therefore from the TM disk. When I re-attach it all, either wirelessly or physically, it seems to see it as a new TM drive and wants to back up the whole laptop.

    Is there a way to force TM to look at what is there and force it to backup incrementally?

    Also...what the hell is a sparsebundle?
     
    Last edited: Jul 15, 2015
  3. Flashy

    Flashy
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    I'd be keen to see any advice too. I have the same thing with my Mac mini – I use an external drive for manual TM backups.

    First was fine, took ages as you'd expect. Then it did incremental backups every hour or whatever while the drive was connected.

    But after disconnecting and reconnecting, it tries to start again but won't because it says there's not enough space on the drive, even though there should be as the drive is bigger than the Mac's HDD.

    Sure it's easily fixed but not when I don't get how it works and don't know what I need to look at.
     
  4. gg13533

    gg13533
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    Sparse

    Sparsebundle definiton:

    1. A sparse bundle is a disk image format introduced in Mac OS X 10.5 Leopard® (.sparsebundle). Like sparse images (.sparseimage), a sparse bundle is a Read/Write format where the disk image only occupies as much space as the data it contains, up to the limit defined when it was created.
    2. Sparse bundles defined - The X Lab
      www.thexlab.com/faqs/sparsebundledefined.html
     
  5. simon12

    simon12
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    I googled it before I posted here and read all that but I don't understand it. I was hoping someone could explain it to me as I simply don't get it!
     
  6. ianbuckley

    ianbuckley
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    If you have TimeMacine set to AUTO and it is using an external drive then you are more than likely to end up with a corrupt sparsebundle at sometime. If you disconnect from the external drive, either by the lose of WIFI, as with a NAS, or just switch your Mac off while TimeMachine is running, the next time it is connected it will tell you it needs to make a new complete copy. You have to be very careful when TimeMachine is running.

    There are ways of repairing the broken sparsebundle, but it does take a long time.
     
  7. Flashy

    Flashy
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    I'm pretty sure it's not set to auto, but I'll happily check and report back. Probably doesn't help that I was using the world's oldest external drive. Might be worth investing in another, I think.
     
  8. malk

    malk
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    Some drives, like external memeory sticks, or memory cards, dont fully erase the data with macs(sigh), i use a memory card for recording vids using a quad copter, and when i have deleted older vids, it says its moved to the trash, but after a few more, the drive is full, only a erase using disk utility wipes the data properly.
    Same as my 500gb externall drive attached to my Airport extreme, that i use for movies, even though when i have watched the film, i drag it to the trash,mac says its gone, to the trash, cool,but, if i select the drive from another source, say the Tv using wifi, the film is still there.( yet mac reckons i moved to the trash 5 mins before),.i think that some of the file is still there.
    Im not sure though, but i have had a few drives that should not have things on, and have less GB than supposed to be.
    very annoying , maybe this is why the drive is full up on your time machine, as it should be deleting older back ups, but maybe this problem is preventing that.?
    My movies HDD is nearly full, yet only has about 10 films on it, acoording to the imac, yet on my TV, it can still see films that i have deffo deleted (or thought i had).
    so thats two examples from two different storge , one wifi, one plugged in direct that both have data on, that shouldnt be there,yet the imac said it deted the data,,, both using up GB that i dont want using up.
    I havent really realised , or thought about this before, just shrugged it off...
     
    Last edited: Jul 24, 2015
  9. MartinPickering

    MartinPickering
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    Do NOT look at the contents of Time Machine's external drive. It has no user-serviceable files or folders, so leave it alone. (It uses a custom file structure and, if you mess with it, it will stop working.)

    Make sure the drive is powered via a UPS to avoid data corruption from momentary power cuts or "brown outs". (Your MBA has a built in "UPS" battery but your external HDD hasn't.)

    Before disconnecting the drive, set Time Machine to "Off" in the menu bar then give it a few minutes to finish what it's doing.
     
  10. alan280170

    alan280170
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    I just back up every 6 weeks or so, it seems to back up quick enough.
     
  11. MartinPickering

    MartinPickering
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    Or simply empty the trash? Moving files to the trash doesn't delete them. (Some video-processing Apps have their own version of the "trash" and it, too, needs to be emptied.)
     
  12. malk

    malk
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    Yes, i empryrd the trash also.
    Yet the file size does not go down after deleting, then emptying the trash.
    The only way to get the GB back, is using disk utility to do a proper wipe.
    I have the same problem with an external 500gb HDD connected to my AEBS, it dosent delete the files properly, even though it is no longer available and i cant see it when i bring up the content folder(on my MAC), yet on another device, ie the TV,bringing up the same folder, the files (which should be deleted) are still there.
     

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