Q: Disk not ejected properly

FWIW I have had the problem with a Plugable USB 3 caddy that goes through a USB 3 powered hub.

I also have it with a OWC Mercury Elite Dual enclosure, which was Thunderbolt. In fact this just destroyed one of my volumes...couldn't repair it. Not happy. I have had "prevent sleep" on, but allowed screen sleep. Won't do that again. At least with the Plugable I didn't get data loss.

I also don't get the problem with flash thumbdrives, not does it happen with SSDs (there's one in my dual bay; the HDD crashed, the SSD didn't). Maybe it's a plot to get us all to buy flash storage....

Well it's been awhile since I commented on this problem but my Buffalo Thunderbolt 1tb drive is still working fine with no issues for almost a year now.

My OWC drive I had which had the problem was moved to my laptop and re-formatted for pc.  And it's a little flaky there too!  You would think Apple would

have fixed this by now.  My iMac is running Yosemite and the Buffalo is hooked directly to usb port on the iMac.  I put it to sleep all the time and haven't had

any problems with DNEP so far.  Hope it keeps working.

Every now and again I have a little look to see how the issue is progressing.

I have had most of the problems mentioned and tried (I think) most of the suggested fixes (Jettison etc).

The issue occurred with USB 3, Thunderbolt and also USB 2 (but only with powered drives). USB 2.0 "self" powered drives and both USB 3 and 2 Thumb drives are fine.

My problems were solved by removing a mains master multiplug with the "eco" facility to switch of several things when the main one was switched off.

Once my external drives were plugged into a separate mains supply I could then use the sleep facility.

The drives now power down and reawaken whenever my (iMac) does.

I haven't yet tried the iMac in the "eco" plug again with the drives in separate sockets to see what happens. I will eventually but it involves moving cupboards and crawling under desks etc so may be a while!

I presume the eco socket was "assuming" that because the iMac was drawing only a small amount of power it had been switched off and, consequently, switching off the other things as it was supposed too.

I think the whole issue is power related but have no idea how/why. The fact that usb low draw items like thumb drives seem unaffected seems to support this but I'm sure someone will have a different experience.

Still think apple ought to try to sort it out somehow but they do hate to admit that they've failed in any way.

In the instructions that come with the LaCie thunderbolt2 drives I read some advice in case of problems:

"Problem: I got an error message telling me that the hard drive has been disconnected

Q: Did it happen when the computer was coming out of sleep mode?

A: Simply ignore this message. The hard drive will remount to the desktop. LaCie hard drives conserve power by spinning down when you set your computer to sleep mode, and when the computer is awoken from sleep, it may not give the hard drive enough time to spin-up from its sleep mode."

Could this just be a minor problem, a mechanical drive that is too slow in awakening from sleep as compared to an SSD hard drive in the latest macs? But then, can we trust this? An error as serious as a drive that was not ejected properly, should be heeded.

I have one Lacie thunderbolt drive (not SSD) which has suffered and also at least once in the past 2 years became corrupted and needed formatting.  I also bought a new cable without any benefit.

This (drive corruption) has happened with other drives as well but is only an occasional event.

Hasn't happened at all (corrupt drives or DNEP message) since my aforementioned power supply change around.

As many people have found - Apple claim to have little or no knowledge of this problem when contacted. I wonder if they can't sort it out so are just burying their heads in the sand.

I suppose the several thousand people affected are only a small proportion of their customer base so not very important.

I am surprised that one of the higher level users haven't found a full solution yet.

I've been having this problem since updating to 10.10.1. Up until 10.10 everything was fine. The problem is with my RAID 2X3 WD My book USB3.

Every day while I'm working on my iMac (late 2012) suddenly dropbox is disconnected, itunes can't find its library, etc. When I try to access the files on the disk, only the folders can be seen and some small files. Disk utility says it can't verify the disks, but once I go into recovery all is fine and they don't need repair.

I've went back to 10.10 and for several weeks all was fine, until recently when I made several reinstalls of the OS, using migration assistant, restoring from backups and so on. Now it happens once again and I've just installed 10.10.1. It was fine for few days and again - few times every day the problem appears. While it is asleep I even got the disk not ejected properly for my time machine firewire disk. This has never happened before. I am so frustrated by these problems at apple. My airplay is also broken and doesn't work at all. I've spent several days in chatting with support, making reinstalls and restoring from backups. I am tired of all of this...

I beg for fixing this issue in 10.10.2 soon!

I am no longer having this problem but my fix probably isn't going to help many others who are having the problem. I just replaced my 2009 Mac Pro which had the DNEP problem happening with at least 2 external drives. This new Mac Pro has a 512GB SSD. I was not able to import or migrate my old settings--tried it but ended up having to erase and reinstall Yosemite on the SSD. I ended up just starting out fresh and reinstalling applications and using iCloud to get some of my data such as Contacts, Keychain and bookmarks for Safari. I am using an OWC Thunderbay enclosure for my 4 hard drives which were inside my 2009 Mac Pro. I have the 2 external drives which were always getting the DNEP message plugged in and no problems. One is a LaCie FireWire 800 drive plugged into the Thunderbolt Display. The other is a Seagate 4TB USB 3.0 drive from Costco.

I don't know if anybody has tried erasing their boot drive and just starting out clean like I am doing. It would be interesting to know if that might fix this problem for others.

I have a new Mac Pro, installed everything from scratch, and am still having this problem.

Fixing this would be great.

Just to add to this... I can confirm I'm getting DNEP on two external drives (usb3) which are both Seagate, 1TB and 3TB (both plugged in directly to the mac). However, they don't disappear from the desktop or the sidebar, they both continue to function. I just get the message popping up every time the mac wakes from sleep.

iMac 27" retina bought new in Jan 2014. Yosemite 10.10.1.

Data was transferred from a Snow leopard iMac with Migration Assistant.

Incidentally, this new iMac will go to sleep even if it's running at a constant 97% cpu load rendering Cinema4D output to an external disk.

Something is wonky with the whole sleep business.

By the way caffiene in the terminal does keep my mac awake and allows renders to run overnight - not possible in the current yosemite because everything powers down to around 5 percent. Hugely annoying to check in the morning and only 7 frames are rendered. My full attention mac does it at 6 seconds per frame, not 2 hours. I digress. Although the mac is not entirely asleep, just very nearly because stuff got done, just incredibly slowly. What the **** is going on there?

I know CAFFIENE won't work for my seagate drives because they go to sleep if not called upon, and neither are mac formatted from the box. I formatted them as HFS as apple recommends.

Why would that matter about how they are seen by OSX?

This is exactly what I hated about Microsoft - half-arsed software released half done. Welcome to Apple without Steve Jobs who got angry when things didn't work. They need a new person like him because this is going to destroy Apple with endless stuff not working. I'm off topic. Sorry.

Using caffeine no external disks have been lost.

RANT END

HI All,

I've had this issue for over a year now. It doesn't look like there is anyway to resolve this. However I have a few questions that hopefully someone here can answer.

History:

Mid 2010 27" iMac. I've got different brands of external hard drives (WD and Seagate) being ejected through the USB 2 ports on the back of the computer and through a powered USB hub. I've also got my printer and sometimes my keyboard being ejected as well. And finally my Drobo external hard drive though firewire connection.

I can't tell you how frustrating this is. Every time I need to print something I have to restart my computer.

So my two questions are:

1. Is this a software issue or a hardware issue?

2. My computer is nearing the end of it's life (I'm a photographer and work it pretty hard) so if I do get the new 5K iMac. Will I have the same issue with things ejecting?

Thanks in advance and please do help me!!

You seem to have it worse than most if your keyboard is also ejecting. How do you know? Now that I think of it, I would have to unplug and plug my keyboard in occasionally on my 2009 Mac Pro which also had some external drives ejecting improperly on Sleep. It would happen when I would plug in my iPhone without waking my Mac first. I never connected that to the DNEP issue.

Since your computer is on its way out, you might get lucky and the problem could go away when you buy a new one. That is what has happened to me. I just got a new 6-core Mac Pro which I did not migrate anything over to. I have all my data on external drives but I set this up clean. Apparently, a new Mac doesn't solve the problem for everybody though. I too wish Apple would figure out what is going on and fix it.

I had the dnep problem with my OWC drive but not with my Buffalo drive.  So I think it's a hardware problem also.  I didn't do anything other than switch

drives from OWC to the Buffalo. 

Here's my update for whatever it's worth. I bought two LaCie D2 drives and connected them via TB2. I did this because I was not getting any "disk not ejected properly" errors from the LaCie Big that is connected via TB2. For the first several days the drives worked fine. But lately I've noticed a new problem. I'm not sure if this is related to the "disk not ejected properly", but it may be so I'm posting here.

When I put my iMac to sleep, the external drives also sleep—at least at first. But shortly thereafter they start cycling on and off, literally every 60 seconds or so.

This of course wakes up my iMac and prevents it from sleeping. I've called Apple and they are useless.

Is anyone else experiencing something like this?