What Does Time Machine Do in a Technical Sense?

Discussion in 'Mac Apps and Mac App Store' started by strwrsfrk, Sep 19, 2011.

  1. strwrsfrk macrumors regular

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    Mar 1, 2011
    Location:
    Arlington, VA, USA
    #1
    My MBA has been backing up to a "Time Machine" partition on my Synology DiskStation for approximately 60 hours now (about 128GB worth). The DiskStation caps out at about 35Mb/s write speed, which I'm sure Time Machine does not achieve. Anyway, I've checked the MBA several times over the weekend, and the data seemed to have been transferred over after about 30 hours. Then came "finalizing backup" and "indexing."

    TL;DR MBA Time Machine backup taking forever.

    So my question: What are the steps Time Machine goes through start -> finish, and what are the approximate ratios of required time for each step?

    This info is not easily found online, so I figured someone here might know.

    Thanks!
     
  2. BrickbookPro macrumors regular

    Joined:
    Jul 26, 2011
    #2
    Not sure of the details... however something doesn't seem right with the time it's taking you. I backed up 400gb of my hard drive with time machine over about 4 hours. This was also over USB 2.0 and not 3.0.
     
  3. eess macrumors newbie

    eess

    Joined:
    Jul 23, 2011
    #3
    any background process running?

    Perhaps a little bit off topic, because I did not use time machine but SuperDuper. I recently found that if my Sophos On-Access-Scanner is activated during backups it will took noticeable longer to finish copying.
     
  4. strwrsfrk thread starter macrumors regular

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    #4
    It's definitely a long time, but since it's using a third-party NAS (not an Apple Time Capsule), I knew it would take much longer than the 35 Mb/s r/w I typically get. Also, this is the "initial" setup which is supposed to take a while.

    Thanks for your input, though. Hopefully when I get back from the office tonight everything will be done.
     
  5. Panch0 macrumors 6502a

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    Virginia
    #5
    in a technical sense...

    A couple of the steps are:
    The main backup job is handled by rsync (remote Synch), which is a *nix program for creating backups.

    I know that mdworker (the indexing engine of Spotlight) comes into play, but I'm not sure which phase it aligns with - probably indexing.

    You can get a lot of information about the process from Activity Monitor. For example, you'll be able to see the utilization of the above processes. I sometimes check the Disk Activity (the reads are the only thing that matter during the backup) and the Network (Data Sent). Your network traffic is probably the slowest part of the chain.
     
  6. gnasher729, Sep 19, 2011
    Last edited: Sep 19, 2011

    gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #6
    I can guarantee one hundred percent that rsync is not involved one bit in a Time Machine backup.


    When you are connected through USB 2.0, the limit is usually about 30 MB per second, unless you are backing up lots of small files, which can take a lot longer. When connected through a wireless network, the limit is the limit of that wireless network; small files are still copied a bit slower but not much slower than through USB. You can open "Activity Monitor" and watch "Disk Activity"; when backing up large files you have typically not many reads/writes per second but many MB/second; with small files the number of reads goes up; I have seen 4000 reads per second, but the MB/second goes down. With wireless, you can check under "Network" how much data is transmitted per second.

    Depending on how your "DiskStation" is connected, Spotlight might not realize that this is a backup drive and tries indexing it. In System Preferences, click on "Spotlight", "Privacy", then add the "DiskStation" to "Prevent Spotlight from searching these drives".
     
  7. BrickbookPro macrumors regular

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    Jul 26, 2011
    #7
    Mine was a Seagate drive and was done as an initial set up :confused:
     
  8. Panch0, Sep 19, 2011
    Last edited: Sep 19, 2011

    Panch0 macrumors 6502a

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    #8

    Ooopps. I see rsync running every time I start wondering why Time Machine is taking forever. I just fired of a backup, and you're right rsync isn't running. Guess that must be coming from one of my many other backup & sync services... :eek:
     

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