Yosemite ejects external drives

I have an imac 5K Retina running Yousemite. It ejects my external drives after the imac goes to sleep. They are Seagate USB 3.0 2 TB and I am not using either one as a Time Machine. Spent hours with Apple online support and did lots of debug, Apple even replaced the mother board on my few months old imac but still have the problem. I got around it by connecting the drive to a powered USB hub. Not a long term solution but hopefully Apple will step up and solve the issue that affects so many.

I have tried combinations using the following:

Thunderbolt:

WD 4TB Mypassport pro

Thunderbolt to Firewire 800 Adaptor

OWC Thunderbolt dock

Firewire 800

16TB G Speed Q

12TB G Speed Q

8TB OWC Guardina Maximus

Lacie 600gb Extreme

Lacie 500TB portable

USB 3.0

WD Essential 2TB Time machine

Mobius 5-Bay raid system as JBOD into which I drop disks as I need them

The only disk that doesn't eject is the time machine.

No issues join my laptop running Mavericks.

Wake up Apple

How does one then "find" their external drive after Apple Yosemite has ejected it? How can I find it and save files to it after it's been ejected?

Thanks in advance.

You can get the ext drive to mount on the desktop 1) Disconnect the drive and re attach it, or 2) Restart your mac. You may try to logout and log back in.

By the way, my experience tells me this issue is not necessarily caused by Yosemite. I have three macs, all have been upgraded to Yosemite two of the macs are late 2009 vintage and the third 2014 imac 5K. The disk not ejected properly problem occurs only in 2014 imac and work perfectly ok with two 2009 macs even though all using OSX 10.10.3

Anyone else with this issue running BackBlaze to backup their external drives? I am suspecting BackBlaze is the source of my issue with the external drives ejecting.

Look everybody -- there could be a score of reasons Yosemite ejects external drives B U T here is one override that WORKS on an old iMac with the latest iteration of OS X 10.10.3 : go into System Preferences / Energy Saver / Power / Computer Sleep / and set for "Never"! And stop all the messing around with cutsy hypotheses! If Apple had any clue, they probably would have fixed this and a bunch of other stuff in the slow and ugly Yosemite.

I'm sorry all this conjecture upsets you so much... (unsubscribe?) The bug with "sleep" I think is pretty much confirmed by everyone, but this is NOT the only thing triggering ejects for many of us. I recently solved my "non-sleep eject" problems by determining I had a bad drive (hardware verified). When that drive would randomly fail and eject it ejected the whole chain. It was a huge pain of process of elimination because until the drive permanently failed, it was impossible to duplicate the error. Having this discussion initially helped me eliminate some basic things and gave me insight into some other things I hadn't considered.

I hope you feel better soon! 😝

This problem is a real PITA and yet another thing to add to Apple's growing list of "It just (doesn't) work"!

I thought it was me at first, maybe accidentally jolting an external HDD that maybe Yosemite though I was ejecting, but no. I get external HDDs ejecting before copying tasks are completed even when the MBP is awake!!!!

Paying Mac premiums are fine IF the things work as expected but the problems these days are more reminiscent of Windows. And as ever, the workarounds seem to involve disabling features and crippling the laptop until such stage as Apple can be asked to find a solution. Yosemite for me has to be the worst of Apple's OS X incarnations. **** sure I will delay installing ANY upgrades until their junk ware has been thoroughly tested in future!!!!

Follow up, after having set my 2012 iMac to never sleep (as opposed to sleep after 3 hours), the external drive ejected overnight on day 5. So, no change there from the usual behavior of Yosemite intermediately ejecting it several times a week whether or not I read/write to it. (Again, this is only with the thunderbolt drive, not the firewire. Cables and port check out and drive did not eject on a windows PC when attachedthere for over a week.)

Then also deactivate all the stuff in Spotlight. Keep deleting all the recommended things that seem to make sense in the posts going backwards. The glitch is probably caused by a combination of apps.

Although this issue is supposedly solved by turning off Spotlight I can report a work around - on my OWC external drive I switched from an USB 3 connection to a Thunderbolt to Firewire 800 adapter. Moving to a different connector solved the problem for me. The drive is used for Time Machine

Count me in...Yos 10.3 with two seagate drives USB..eject at sleep...then frequent message even though they are not showing in devices. tried energy saver tactic - failed. do not want to shut down or leave not a sleep..... ...interestingly it does not seem to be an issue with my card reader.

Will try spotlight method

Have also tried Jettison and a seagate fix to no avail.

Also i have to shut down to get imac to recognise drives, so i may as well shut down each time😠

Very disappointing when we have all laid out significant cash...i have a Dell/windows for work - no problems

Interesting that its 2015 and Apple hasn't fixed this bug. Anyways, this solution seem to work for me too thanks 🙂

I can't find to turn off "EXTERNAL DRIVE" in Spotlight list – WHERE is this please? Ejected SIX times today alone. Thanks in advance - making me CRAZY.

In Spotlight, you should see 2 tabs (Search Result & Privacy). Go to the Privacy tab and if you have the "EXTERNAL DRIVE" still connected to your computer, click the + sign to add the drive. Thats what I did.