Yosemite ejects external drives

As stated earlier, my old WD H/D worked well on my old iMac but never worked well with my new Macbook. So the Apple geniuses tried everything and eventually had me get a new WD H/D. The same issue continued.. Last month they sent me a free Seagate H/D and that solved the problem. I am surprised but grateful.

I'm a new member to this club. I just set up a brand new 5K iMac and as part of the migration from my old 2011 MBP, I pulled out a secondary SSD I had installed in the optical bay and dropped it in a drive dock connected directly to the iMac over USB 3. It never skipped a beat on the SATA connection in the MBP but now every time I come back to the iMac I have the drive eject error, but at least it remounts each time.

I had been having a very similar problem with drive ejects from an OWC Thunderbolt 2 Dock which I put down to the dock because they seemed to happen mostly when I was unplugging stuff – although I swear I was not bumping any other connections enough to cause a disengage of the contacts. They are pretty solid connections! So now I wonder if it was an OS/hardware bug on Apple's part.

This thread is over a year old, has 55 thousand views, and still no fix.

I have a Mac Pro (2014) and a Macbook Pro 15" late 2013. I have a Lacie 8Tb on the Mac Pro and a GRAID 4TB on the Macbook. BOTH drives have this exact symptom on each machine and do it EVERY day. I am on El Capitan now but it also happened on previous OS X versions. From everything I've read, this looks like a Thunderbolt driver or firmware issue. It's beyond me that Apple doesn't know about this because it's fairly easy to reproduce.

I have not switched to El Capitan. I HAVE however, disconnected the drives that were doing this, and the other drives have not. This makes me wonder if the drives were specifically having problems (they happen to be Lacie, Fantom and WD) the ones that are fine are Lacie rugged, WD My passport, WD

My book. Sorry I can't tell you the models of the ones not working -- they aren't written on the drives. They are older drives, however.

So, you might try to see if some drives are doing this and others aren't.

I had the issue where my external G-Drive was not ejecting when putting my Mac Pro running El Capitan to sleep - so when I logged back in I would always have multiple Disk Not Ejected messages. Not a solution from Apple, but I found that an app called Jettison works really well. Its a couple of bucks, but does the job. You can also try Mountain, but I did not have as much success with that. Hope that helps someone out there 🙂

I am now connecting all 3 external HD to a new hub. It appears that only the external HD that has time machine installed will do this random disconnect. Then when I partition one of the 2TB HD to have 1TB dedicated for time machine and 1TB dedicated for just storing files, if the time machine partition disconnect the entire 2TB HD will disconnect with it. Any other external HD that doesn't have time machine did not disconnect.

Just adding to the pile, in the interest of input which might reveal something...

After one year of excellent performance, my 2013 iMac has suddenly exhibited this false(?)-eject behavior. El Capitan 10.11.3. The external HDDs are four 2TB Hitachi in a 4-bay enclosure (OWC Elite pro Qx2) connected via USB 3.0.

If one looks for recent activity that night have triggered this, the one 'unusual' thing I did do, just yesterday, was to update my iPod Touch to iOS 9.2.1, via iTunes on the iMac. But I've done one or two other iOS upgrades in the last year without incident. I try best I can to disable any and all syncing between devices. FWIW, Spotlight is entirely enabled on the Touch, and for the iMac I'm considering the disabling steps discussed in this thread.

Another misbehavior that popped up when the ejects and their warning messages appeared was that iTunes started playing back erratically and/or distorted. (iTunes > BitPerfect > outboard DAC; music files are stored in two of the four ext HDDs.) As of today, accessing the HDD for music (ripping or playback) seems to trigger the eject behavior, for all 4 drives.

Also, the entire system now stalls for several seconds upon Shut Down. I haven't had a chance to try Sleep modes.

I read through most of this thread, and what with all the many various devices, OSs and connections described, I think this points to a hardware / firmware problem on Apple's end.

Furthermore, this issue seems to go back several years. I had to face this a couple years ago on a 2008 iMac Snow Leopard, with the same OWC enclosure / HDDs. In that case, I had the enclosure (only) replaced and it seemed to resolve the problem for a while, but the subsequent ejects were at least infrequent. When this HDD / enclosure migrated to this newer iMac (shipped with Yosemite) the problem went away altogether. Until today.

Which makes me further suspect hardware / firmware. And worry about HDD content damage.

Just for disclosure, I'm an atypical user in that I'm deliberately detached from most convenience apps and syncing:

No USB hub (all connex directly to the iMac)

No Time Machine (don't like it, backups via SuperDuper)

No Spotlight (don't like it, only use command-F)

No iCloud (or any cloud)

No syncing between devices (there is only the iMac and Touch)

WiFi disabled 99.99% of the time (Airport Extreme)

All this in the interest of simplicity and/or security. Which makes the hardware / firmware suspicion grow when I see the ejects happen.

Anyway...

Fortunately, I've got a couple years left on AppleCare (I might need 2 years to resolve this). I will approach them with this. I'm sure they will immediately suspect the 3rd-party drive / enclosure set up (all vendors do this), but I will direct them to this thread, and note there are several others like it. I'd like to hear their input on Spotlight disabling before I actually try it.

If anything insightful comes of it, I'll post back here.

Hmmmm...

The day after I posted above, after booting up in the morning (shut down the previous evening), I promptly experienced a brief eject episode, and then nothing more during the rest of the day. The next day, and afterwards, normal behavior. Seemingly fixed itself. ? ? ?

Unless eject issues return, I can't really bother AppleCare with something that's working here, I guess.

But I sure will be wary the next time I upgrade iOS on the Touch.

Spoke too soon.

Ejects started all over again, and now worse than ever. Can't even keep the externals visible on the desktop for more than a few minutes.

It also appears I've lost one of the 4 drives in the enclosure.

I can get the externals to show up on a 2008 iMac Snow Leopard, and stay put, and open the individual drives, but it is really slow.

So I still suspect the 2013 iMac, but it's hard to prove. I've been through this once already. It lasted for months.

Not looking forward to this round.

This suddenly got worse for me also. After the last OS X update time machine is ejecting my external HD several times an hour. Maybe we should write this on a product review all over the internet to see if the drop in product sales will get Apple to take this issue serious. Apple management would love to see that wouldn't they.

Is this fixed in El Cap? It's driving me crazy and I am sure it doesn't help the integrity of my hard drives that they keep being ejected improperly. I recently bought a thunderbolt SSD drive and for some reason that seems to be the one that gets ejected most often, even while I am using it (I use it for running samples from in music production so this is really making that hard). But my other hard drives also get ejected, just not as often. I nearly bought a replacement Thunderbolt cable thinking it was faulty before I came across this thread, thunderbolt cables are not cheap so I nearly wasted a lot of money. I tried all the suggestions so far - turning off hibernation has definitely made a difference but not 100%. Turning off spotlight did nothing apart from make it impossible to find anything. The disk itself is functioning fine. This really needs to be fixed, it's a serious bug, why are they ignoring it?

Problem exists in El Capitan.

My final solution was to remove my USB 3 drive that I used for Time Machine and bought a new drive with Thunderbolt 2. The Time Machine drive was the last drive that was having the problem.

2 other drives are Firewire 800 using Firewire to Thunderbolt adapters. They were having problems, but I believe I erased them They were both Superduper clone backups so I didn't care about erasing them. Once erased the problem of them ejecting went away.

I have one other Thunderbolt 2 drive attached and that store my main data. Recently it was disconnecting, but I'm pretty sure because I was bumping the cables. I have a feeling the Thunderbolt connection into the computer is not rock solid. I'll have to do a shutdown and reset the connector just in case its a little lose, otherwise I'll keep my hands away.

Yes, the problem still persists in El Capitan.

I did make my way to a knowledgeable AppleCare rep. Spent an hour on the phone with no solution (I didn't expect one). But, late in the conversation, he speculated that when I updated iOS via iTunes, it might have applied a routine update to the iMac USB drives. Which might explain the sudden eject behavior after a year of good performance. But this is difficult, if not impossible, to discern.

So I went back to OWC (the vendor for my problematic Qx2 4-bay enclosure), and they agreed to send a new Qx2 replacement. I tried to negotiate an exchange for a Thunderbolt enclosure, just to try a completely different connection, but no go. So I get to babysit this all over again.

After all the time, it's still very unclear what causes this. There are several threads on this here on Communities, some going back a few years. Despite that, I wonder if these occurrences are relatively few, and that's why Apple doesn't respond.

Or if there are so many scenarios – many different hardwares, OSXs, external drive configurations, intermittent episodes – that it makes it near impossible to resolve. I still think there's some voltage issue that makes sensitive external go buggy.

If this new enclosure fails, I'll try to return for refund and go back to individual enclosures. Thorough testing here indicates that those setups appear to work properly. Until they don't, I guess.

Pretty helpless feeling not being able to trust your storage and backups.

I have the latest version of El Capitan 10.11.3 on a brand new Powerbook with a 1 TB encrypted external drive (required in healthcare).

This drive disconnect many time a day during my work.

This latest version does attempt to reconnect when it happens.

This must be a deep "hidden feature" of OSX.

It would be good to hear from Apple on their awareness of this issue.