Forgetting to unmount drive before unplugging

Discussion in 'Apple' started by Ian Gregory, Apr 19, 2008.

  1. Ian Gregory

    Ian Gregory Guest

    Last night I plugged in my Time Machine drive and let it get on with its
    thing. A while later I heard the drive spin down and without thinking I
    unplugged it. Of course a box popped up saying I should have unmounted
    it first - doh! Anyway, I plugged it back in and it mounted fine and
    passed a Disk Utility verification so I am assuming it is OK.

    Before spinning down due to inactivity are the buffers flushed? In other
    words, whilst not being recommended, is it normally safe in practice to
    unplug an external FireWire drive that has spun down without first
    unmounting it?

    Ian
     
    Ian Gregory, Apr 19, 2008
    #1
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  2. Ian Gregory

    billy Guest

    Syncing a firewire disk (flushing its buffers) can take up to 30 seconds
    after the last write to it, or up to 30 seconds after dismounting it, but
    it will not be spun down until after this happens.

    Generally speaking, you can get away with unplugging a mounted but spun
    down device - I deal with this occaisionally in my work. But, do I think
    it's an OK thing to do? No. Sometimes it takes two or three attempts
    to mount again, once in a while I have to remove everything else from
    the firewire bus to get an improperly disconnected disk to mount. But,
    have we ever lost any data (over many years)? Nope...

    Billy Y..
     
    billy, Apr 19, 2008
    #2
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  3. Ian Gregory

    Bob Harris Guest

    I lost a Time Machine backup set by putting my MacBook to sleep
    incorrectly.

    I had a Time Machine backup going on my MacBook. I clicked on the
    (X) in the progress bar to stop the backup so I could put my
    MacBook to sleep. Eventually it did stop. Then I closed the lid
    and took my MacBook. What I forgot to do was to manually unmount
    the network drives before closing the lid.

    When I got to work, I got pop-up messages say the network drives
    could not be found. Nothing I could do about it then.

    When I got home, Time Machine was unable to find the network
    backup.

    I used Disk Utility to try and repair the .sparsebundle, but it
    just said it could not find a mountable volume.

    There is a discussion thread on this over at the Apple forums.

    Personally I think this is an area that Apple needs to improve the
    robustness. Maybe includes logic to cleanly unmount network
    volumes before really putting the Mac to sleep.

    Bob Harris
     
    Bob Harris, Apr 19, 2008
    #3
  4. Ian Gregory

    Eric Lindsay Guest

    I lost a WD 1TB My Book Studio Edition triple interface drive with a
    Time Machine backup when I accidently powered it down without
    unmounting. I never did find anything that would let me connect my iMac
    to the drive again via Firewire (the iMac Firewire ports still work with
    a different Firewire drive).

    Luckily the USB connection continued to work, so I was able to use that
    instead of Firewire. The Time Machine backup seemed to be intact over
    USB. This may simply be a WD Firewire problem. Does seem to indicate I
    need to take more care to manually unmount external drives. However I
    didn't buy a Macintosh so that I could do computer things manually.
     
    Eric Lindsay, Apr 21, 2008
    #4
  5. Ian Gregory

    billy Guest

    Can you try the disk's firewire port with a different computer to
    determine if it still works?

    If your computer hasn't been restarted since this happened, you
    could try that, too. This would clear any possible stale info
    about the disk being mounted...

    Billy Y..
     
    billy, Apr 22, 2008
    #5
  6. Ian Gregory

    The New guy Guest

    I lost a WD 1TB My Book Studio Edition triple interface drive with a
    Wow - you'd think they would build some feature into the system that
    would preclude that from happening. Sooner or later we all do things
    like that.
     
    The New guy, Apr 22, 2008
    #6
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