Every time I close the lid on my macbook air, my external hard drive seems to spin up for about 5 seconds every 30 seconds, and this will go on continuously, even for several hours. The noise itself isn't too loud, so I don't really have a problem with that, but I'm worried it might damage the hard drive.
Is this normal OS X behaviour (I'm on Mountain Lion, sleep mode 3), or is it specific to my model of hard drive (Samsung 1tb USB 3)? I read that Mountain Lion will supposedly check emails and perform updates during sleep, could that be the cause?
If it doesn't harm the hard drive, I'm not too worried, but if repeated spinning up will exert extra strain, I'd like to find a way to stop this happening.