iMac waking up external hard drives randomly from sleep

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iMac waking up external hard drives randomly from sleep

I'm running a late 2013 27-inch iMac with Yosemite and been experiencing a strange issue with it. Whenever my mac is sleeping my external hard drives (I have an external LaCie 1Tb Firewire disk and a D-Link NAS connected to it) keep waking up at random intervals. Basically the drives just spin up at random intervals while the iMac is sleeping and stay on for about 30 seconds before going back to sleep again. The Mac itself doesn't wake up, just the external hard drives. This doesn't happen when the mac's off, just when it's sleeping. I have just the "put hard disks to sleep when possible" selected from the energy saver, everything else is disabled including Power Nap. Neither of the external drives in question is configured for TimeMachine.

Anyone experiencing a similar situation?

iMac, OS X Yosemite (10.10)

Posted on Nov 7, 2014 12:44 PM

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Answer 1

Best reply

mdpny

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5 points

Nov 8, 2014 7:17 PM in response to Jay_Finland

I have the same issue, except with a 4TB G-tech G-Drive. Started waking intermittently after I installed Yosemite. Have "put hard drives to sleep" checked and "wake for network access" unchecked. Still happening. Apple, any thoughts?

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Answer 2

mdpny

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5 points

Nov 22, 2014 11:15 AM in response to Jay_Finland

did you find a way to fix this?

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Answer 3

Jay_Finland Author

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11 points

Nov 22, 2014 11:36 AM in response to mdpny

Nope, no fix yet. So now I'm shutting down the iMac whenever I'm not using it to prevent the drives from spooling up unnecessarily.

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Answer 4

mdpny

Level 1

5 points

Nov 22, 2014 11:49 AM in response to Jay_Finland

That *****, same deal here. Wish someone from apple would respond...

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Answer 5

Ralph9430

Level 7

21,756 points

Nov 22, 2014 12:30 PM in response to Jay_Finland

Do you by any chance have Power Nap turned on? If so the Mac will come to life somewhat to perform Time Machine backups and check email. The settings for this is in System Preferences > Energy Saver

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Answer 6

mdpny

Level 1

5 points

Nov 22, 2014 1:23 PM in response to Ralph9430

Powernap is turned off. Don't know what is causing it. Wasn't an issue until I upgraded to Yosemite

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Answer 7

tbirdvet

Level 6

13,731 points

Jan 27, 2015 7:24 AM in response to Jay_Finland

I have the same issue on my 2012 Mini running Mavericks. I thought it might be the hard drive with my Macally enclosure so I changed the drive and same issue.

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Answer 8

Apr 9, 2015 10:31 PM in response to Jay_Finland

I too have this exact same issue with your exact setup. I have an external HDD and also a 3.5" sata drive plugged into a USB3.0 dock and both HDD's spin up randomly. About every minute or so and nonstop!! This is ridiculous. PLEASE APPLE ADVISE US!

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Answer 9

Apr 10, 2015 2:29 PM in response to Jay_Finland

OK I found out what it was!! I have a USB hub attached to my iMac. Its a USB 3.0 4 port hub from ebay. For some reason when it is attached, the computer constantly spools up the HDD's over n over again and turns on and off the audio making a popping sound. So now that I have unplugged it, it's all good. All my external drives stay asleep. I'm going to try and order a name brand hub to see if it makes a difference.

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Answer 10

Apr 22, 2015 9:00 AM in response to Jay_Finland

X-post from Time Machine Runs While iMac Sleeps

I've got a 400GB Western Digital ELements drive connected via USB running my Time Machine backups. While the iMac computer is sleeping (not display), the drive spins up and spins down almost every minute. I tried bypassing a USB hub, no luck. Then, I plugged it into another iMac and had a revelation!

The TM somehow had a master boot record partition table! Unbelievable! I'm shocked the initial TM backup didn't repartition the disk.

Anyway, make sure your TM backup has a GUID partition scheme. Open Disk Utility, click on the corresponding disk in the left-hand side list, bottom most right line of information should say "Partition Map Scheme : GUID Partition Table" and NOT "Partition Map Scheme : Master Boot Record".

There's no reason AFAIK for a TM to be partitioned with a MBR table.

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Answer 11

May 15, 2015 12:00 AM in response to Jay_Finland

Same issue - Mac Pro (late 2013), external thunderbolt 3TB G Drive spins up at what seems like completely random intervals.

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