Does Time Machine verify backup data?

Discussion in 'Mac Basics and Help' started by Let's Sekuhara!, Oct 6, 2009.

  1. Let's Sekuhara! macrumors 6502

    Let's Sekuhara!

    Joined:
    Jun 30, 2008
    Location:
    日本
    #1
    OK, here's the deal:
    I'm doing an initial backup to a Time Capsule and I want to make sure all my data was copied successfully.
    Does Time Machine verify that the data was copied successfully or does it just send it and hope everything copied alright?

    I know this is the kind of question only the Apple developers would know for certain, but hey, sometimes folks on these forums are surprisingly knowledgeable so I figured I'd ask here.
     
  2. BlueRevolution macrumors 603

    BlueRevolution

    Joined:
    Jul 26, 2004
    Location:
    Montreal, QC
    #2
    All modern networking protocols include some means of detecting and compensating for data corruption. I don't think Time Machine deliberately verifies, but it is sending data over a reliable connection.
     
  3. Let's Sekuhara! thread starter macrumors 6502

    Let's Sekuhara!

    Joined:
    Jun 30, 2008
    Location:
    日本
    #3
    Thank you.
    Perhaps I should be more specific though.
    My girlfriend managed to slam the collapsible futon onto our apartment floor, shaking the entire apartment during the backup.
    I just want to make sure that the impact of that didn't mess up the writing of the data from my Mac to the Time Capsule.

    I am super-paranoid when it comes to matters of data back-up and potential disk corruption. I have used computers long enough to experience the pains of lost data. Frankly, I shouldn't even be typing these words to you now since the vibration of my fingers hitting the keys might interfere with the MacBook reading its hard drive and sending that data to the Time Capsule.
    We are talking about a 5400 RPM spinning platter trying to copy 250GB of zeros and ones with 100% accuracy. What are the chances it will succeed?

    Maybe I'm being ridiculous but... better safe than sorry, right?
    What if I end up having to restore my entire computer from this backup at some point in the future? I don't want to leave anything to chance.
     
  4. Tumbleweed666 macrumors 68000

    Joined:
    Mar 20, 2009
    Location:
    Near London, UK.
    #4
    Two things
    1) Do an occasional 'test' restore. Pick a file at random and restore it it to a location other than the original (so you dont overwrite that). That will check that TM and the disk is working.
    2) Take off site backups, either via writeable CD/DVD, external HD you leave somewhere else, or an online service. TM can't protect against fire/flood/theft or a TM bug.

    p.s. To answer your original Q, when TM takes a backup, it doesn't appear to be verifying, however as per a previous poster, there isa lot of verification going on at 'lower levels' (links between computer and disk, disk controller and disk, so forth), so its pretty much redundant to verify writes to an HD (as oppsoed to a DVD where error rates are much higher.
     
  5. gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #5
    If she slammed the futon onto your Time Capsule, I would worry, especially if the case is broken. If she slammed it onto the ground, no need to worry. It is a hard drive, not an earth quake detector. And I'm quite sure that any harm to a hard drive will _not_ destroy some data, it will kill the whole hard drive. It either works and has correct data, or it doesn't work.

    BTW. A bit of googling found a Hitachi "SimpleTough" drive that survived _one_ drop from _nine feet_ onto concrete (four drops killed it though).
     
  6. BlueRevolution macrumors 603

    BlueRevolution

    Joined:
    Jul 26, 2004
    Location:
    Montreal, QC
    #6
    I doubt it was running at the time. Hard drives are much more durable when parked.
     

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