Question about time machine...

Discussion in 'Mac Basics and Help' started by Mjmar, Feb 13, 2009.

  1. Mjmar macrumors 65816

    Joined:
    May 20, 2008
    #1
    I am currently backing up a mass amount of data to an external hard drive, and I may need to stop it from backing up in the middle. If I click stop backing up and unplug the hard drive will it continue in the same place the next time I plug it in?
     
  2. DoFoT9 macrumors P6

    DoFoT9

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    Jun 11, 2007
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    Singapore
    #2
    hhmm this is a very good question. i am presuming that it will indeed continue from the place where it last stopped.

    i base this assumption on the fact that each time it backs-up it checks the previous backup with the current data. on the other hand, if you cancel the backup it may delete everything that was backup up..

    so i dont know really... stop it and give it a go haha.
     
  3. Mjmar thread starter macrumors 65816

    Joined:
    May 20, 2008
    #3
    Also, say I don't have enough space on the hard drive in my mac. Will I be able to delete a file from the internal hard drive, and use the external hard drive, which is part of time machine to view those files whenever I want? Or will i need to do that on the side?
     
  4. DoFoT9 macrumors P6

    DoFoT9

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    #4
    yes you will be able to do that.. but i daresay you will only be able to Read Only the files.. if you want to save/modify them then you will have to save to your internal HD...which kind of defeats the purpose
     
  5. DeusInvictus7 macrumors 68020

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    Kitchener, Ontario
    #5
    He can just partition his Time Machine drive. For example, half of the drive would be dedicated to the TM backups, and then the other half would act as a simple external drive, where he can read AND write/modify his files when he wants.

    Hope that helps.
     
  6. sickmacdoc macrumors 68020

    sickmacdoc

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    Jun 14, 2008
    Location:
    New Hampshire
    #6
    I honestly don't understand this advice. I must be missing something here.;)

    You can write additional files to an un-partitioned drive used with TM without any difficulty at all, so that is where I am not following the advice. Since TM stores its entire backup hierarchy in a single root level folder (Backup.backupsdb or similar- I forget the exact name) other files can be written to the remaining drive space outside that folder fine with no partitioning required. Writing to a drive that TM uses for its backup folder will work equally well whether the drive is partitioned or not. So what am I missing?:confused:
     
  7. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

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    Apr 6, 2007
    Location:
    Portland, OR
    #7
    That kind of defeats the purpose of a back up doesn't it?
    Just get another hard disk, besides if you run out of room on your time machine disk it will start deleting old stuff.
     
  8. DeusInvictus7 macrumors 68020

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    Aug 13, 2008
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    Kitchener, Ontario
    #8
    Really? I didn't know you could add files in the same partition as the TM backups. Good to know.

    Maybe I was thinking of having a NTFS partition...that would have to be separate right?
     
  9. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

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    Apr 6, 2007
    Location:
    Portland, OR
    #9
    Time machine won't back up to NTFS. OS X won't boot from NTFS, why would you ever want an NTFS partition in an OS X environment?
     
  10. DeusInvictus7 macrumors 68020

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    Aug 13, 2008
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    Kitchener, Ontario
    #10
    I don't know, I don't remember where I was going with that. The part about TM, I know it won't back up to NTFS. But anyway, I don't remember what I was trying to get at.
     
  11. DoFoT9 macrumors P6

    DoFoT9

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    #11
    ok so here is the low-down people. (lol).

    Time machine creates a disc image (sparse if you must know) on the drive. a sparse disc image is one that can expand or decrease the size if needed, its not like an ISO image where if you specify you need 17.4gb it will take up the whole 17.4gb. when you create a sparse image you can set the maximum size, say 18gb. as you add data to it the image will eventually fill up. just think of it as a flash drive.

    so this is basically what happens on your backups. a sparse image is made, and inside of that is a folder that is the original backup. this original backup contains EVERYTHING from your hard drive. if you backup again another folder is created. Time Machine goes through and checks for changes and puts only the new changed folders/files into this new directory. bla bla bla and it keeps going forever.

    so, because there is only a disc image created, you can use it to store other things!! i think its a great idea from apple, especially with the whole sparse image thing, basically because it wont take up the whole intended space immediately.

    anyways..
     
  12. Sullycanpara macrumors newbie

    Joined:
    Jan 24, 2009
    #12
    to answer one of the original questions, when you are doing a backup in Time Machine, if you need to stop the backup at any time, you can pick right back up the next time you come back to your computer. Just read that in some product knowledge I did last week :)

    Tim
     
  13. zombitronic macrumors 65816

    zombitronic

    Joined:
    Feb 9, 2007
    #13
    I've learned about sparse bundles and images recently through my own attempts at backing up over a network. I'm not crazy about the sparse files and I'd much rather have the backups stored within a single Backups.backupdb folder, just like when you back up to a disk connected locally.

    You get something like:

    Backups.backupdb
    iMac​
    Backups​
    Backups​
    Backups​
    Backups​
    Mac Pro​
    Backups​
    Backups​
    Backups​
    Backups​


    Although, if you had your backup drive connected locally to your iMac and across the network to your Mac Pro, you'd get something like:

    Backups.backupdb
    iMac​
    Backups​
    Backups​
    Backups​
    Backups​
    Mac Pro.sparsebundle

    So this is how I've come to understand network backups to work. However, the following is copied directly from Apple's Time Machine page:

    Back up the whole family.

    The moment you choose a Time Machine drive, a single folder is created on the drive. Inside this folder is a subfolder for each Mac being backed up. (Yes, multiple Mac systems can share the same backup drive.) And within each subfolder is another list of folders — one for every backup performed on that Mac. Time Machine uses a standard file system to store all of its information. Nothing hidden anywhere.


    From what I've seen from my networked backup experiences and from what you're saying here, what Apple is officially stating is simply not true. They're describing what would happen if you went from machine to machine plugging in your drive locally and backing up via FireWire or USB or internally.

    So which way does it really happen?

    I'm weary of the sparse images because if something goes wrong with the image, there go all your backups. If something happened within the folder structure, I'd assume that you'd only lose that backup increment within the folders created by local backups.

    Edit: I was mistaking the Time Machine page for the Time Capsule page. As it turns out, Apple's statement is correct, if you "share" the same backup drive over sneakernet.
     
  14. DoFoT9 macrumors P6

    DoFoT9

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    Singapore
    #14
    interesting experience you have there. i have never backed up multiple computers to a single external HD, i only have my Time Capsule to backup to so my experience is only based on that.

    on the Time Capsule, i open it up, then i am presented with my folders, and 3 sparseimages, one for each computer. now this is wrong according to apples claims, but im not sure if you have to do it a different way to how i did it :confused:

    EDIT: actually i think what they are saying is true, to some extent. there is the

    •sparseimage, inside the spraseimage is a folder named "latestbackups.backupd" and another called something (cant remember).

    if you go into the "latestbackups.backupd" you see the last backup, it normally isnt very big because it only has the last backup.

    inside of the other folder it has a whole bunch of other backups, which are named with the date of the backup.

    22012009​
    25012009​

    and so on and so on...

    does that make any sense?
     
  15. zombitronic macrumors 65816

    zombitronic

    Joined:
    Feb 9, 2007
    #15
    I completely get what you're saying. Time Capsule basically uses the network backup method, i.e., sparse images. This is actually exactly what I was wondering. I wanted to know if Apple somehow got around this method of backing up with their Time Capsule product. They did not.

    I guess this will be the method that Time Machine will be using while backing up over my network. Like I said, I'd really like the regular folder method of backing up due to the fact that if a sparse bundle goes corrupt, there go all your backups for that particular machine. With the folder method, you're only screwed if the whole backup drive goes corrupt, in which case, you're screwed either way.

    My only idea of making the folder method possible over the network would be if you had your computers daisy-chained together via FireWire so that the hard drive would appear locally mounted on each machine. To do this, you'd need some long FireWire cables or close computers. My computers are in different rooms and I'd rather keep my setup neat by using just ethernet.

    A newer proposed version of the IEEE 1394 (FireWire) standard mentions FireWire-over-ethernet. I guess this would let you mount a network drive as if it were locally connected to your computer.

    If you've ever done 'Get Info' on a locally mounted drive, you'll notice that 'Format:' will be listed as Mac OS Extended (Journaled), or whatever it happens to formatted as. If you 'Get Info' that same drive on another computer after you've mounted it as a network share, you'll notice that the 'Format:' will be listed as AppleShare. I imagine that with FireWire-over-ethernet, even a network share could be mounted as the real Mac OS Extended (Journaled) format.

    If you connect a FireWire drive to your computer and then daisy-chain that computer to another with a FireWire cable, the FireWire drive will mount across that FireWire network on the other computer. If you 'Get Info' on this drive, you'll see that its 'Format:' is listed as its actual Mac OS Extended (Journaled) format. This would create backups with the folder method.

    Unfortunately, FireWire-over-ethernet doesn't exist yet (at least not that I've found), so any network backups will have to be done with sparse images. Which brings me to my final question on this matter. If anyone has a technical answer to this I'd be very grateful.

    WHY does a network backup create a sparse image instead of just another hierarchy of folders for the backups?
     
  16. DoFoT9 macrumors P6

    DoFoT9

    Joined:
    Jun 11, 2007
    Location:
    Singapore
    #16
    ok i see your point, loosing that sparseimage would create A LOT of problems. ive been thinking about the whole spraseimage idea and i think that there are a few reasons for using them.
    • sparseimages can be set to a certain size on creation - i dont actually see the advantages though
    • sparseimages only take up the space that is on the disk image, as opposed to say a .dmg or .iso
    • can have passwords/encryption put on them, as opposed to folders which anybody can access

    thats about it for the time being, but i think the last two the major reason why its used. security & space..

    wow that is some intense thinking!! i most definately have heard about firewire over ethernet, but no idea how to do it. ill research for a bit later on 2day after cricket. see if i can get anything happening for you :)
     

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