External harddrive keeps turning on and off

Discussion in 'Mac Basics and Help' started by thebard, May 11, 2011.

  1. thebard macrumors newbie

    Jan 2, 2009
    Hi all,

    I have an external 1.0 TB WD MyBook hard drive attached via Firewire 800 (the square looking cable) on my MBP (Snow Leopard) that I've had connected for the past two days. I have Time Machine set to backup every hour. Obviously it turns on when doing backups. But strangely though, the harddrive keeps turning on and off maybe every 5-10 minutes. I'm not opening Finder when this happens (which I know would spin them up), nor am I doing anything that I know of with the external HD.

    Any thoughts or suggestions? I'd rather not having them do this for wear and tear reasons, and the noise is kind of bothersome.

  2. GGJstudios macrumors Westmere


    May 16, 2008
    If by "turning on and off" you mean spinning up and spinning down, it's normal. The drive spins down when it isn't being used. It will spin up when doing things like opening or saving any files, even if you're not opening them from or saving them to the external drive. Finder makes all connected drives ready for such operations because it has no idea which drive you intend to access. Other actions can also cause drives to spin up; it's not just Finder activities. It won't hurt the drive, as it's designed for such activity.
  3. thebard thread starter macrumors newbie

    Jan 2, 2009
    So even if I'm not accessing of using these files (it's only a backup drive) it sounds like it still will spin up the drive?
  4. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    The drives spin up on command from the OS. I've always thought there were some real oddities due to a file on the external drive still being "remembered" by the OS. Nothing you can do about it though.
  5. discounteggroll macrumors 6502


    Aug 6, 2006
    Greenwich, CT
    TM is set to automatically backup, what do you mean "having it backup every hour"? If nothing is set to read from/write to, it will wake and go to sleep as necessary.

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