Disk not ejected properly

I mentioned this before and was surprised to see that no one responded.

I've had some success with Jettison. It's an app that automatically unmounts external drives when you put the Mac to sleep, and then mounts them when you wake it up. It's not perfect, and I still had some DNE errors when using it, but it worked about 90% of the time.

I've been blissfully outside of this issue for some time, because I found an external drive that doesn't suffer from the problem: a LaCie Little Big 2. The problem is it's a very limited capacity (super fast for video/photo work), and I'm running out of space. So now I will have to buy a larger external drive or an enclosure like the Thunderbay IV from OWC, and I know from previous experience that I will get DNE errors when I go in that direction.

Another thing I've considered is just leaving the Mac on all day, and then manually unmounting the drive before I put it to sleep at night. This is a pain, but it would solve the problem without burning out a fan.

My understanding is that an SSD only Mac would have less of an issue being on 24/7, because it requires less cooling, but I may be wrong about that.

Hi PB, I have 2 brand new 2015 MBP's running 10.10.5 and both have issues with a WD 2TB USB 3.0. I've been pushed up to L1 Support Tech and they couldn't figure it out. Now I have a Genius Bar meeting and I don't think there is going to be anything that they can do. Tremendous waste of time and very disappointing. There is clearly something that Apple is not testing well enough. It took me forever to get to page 29 of this thread so I didn't read everything. Is Apple responding to any of this at all???

Apple gives the advice to do a Power and PRAM reset on all hardware, and it helped me (mini, 10.9, FW800x3)

Nobody else here seems to know about the official response from Apple, but it worked for me.

Genius bar tenders should test this first, imho.

NuXPeR wrote:

Upgraded to El Capibullshit and the problem is worse than ever. Used to only happen when the computer was idle or waking from sleep but now happening all the time, even while accessing the drive.

I'm not seeing that behavior at all with four external drives attached, and the Mountain.app installed. If it's happening all the time, I suspect a problem with your drive, its enclosure, and/or its cable.

UPDATE: Returned my refurbished DataTale enclosure a few days before the end of the warranty to get a Amazon refund. I figured there was something corrupted in the firmware that caused the drive to act up when it exact duplicate enclosure runs perfectly. Since I love the enclosure and set-up for it with multiple drive sleds, I ordered a new one with hopes it would work better. Well, it arrived yesterday and immediately gave me the same disconnect problem when hooked up to it's eSata port. Worse, it somehow corrupted the hardware start-up files in the system library ( HWNetMgr, HWPortDetect, etc in the StartupItems folder). I had to do a reverse clone from my OS BU drive to fix the files. So, I then tried running he enclosure on it's FW800 bus and viola! I have had no problems thus far.

Personally, I still now think here is some kind of firmware issue with some enclosures and Mac OS. Whatever it is, I haven't the slightest idea, but wonder if it doesn't have something to do with these HW start-up files that fail to mount the hardware when coming out of sleep. After all hess got corrupted somehow when using he replacement drive.

If this enclosure can continue to perform well in FW800, I'll be satisfied since I use the enclosures for back-up only and while eSata speeds are preferable, FW800 will do as long as it behaves.

So many users seem to be having trouble with this and the fixes are so varied for different users, it's hard to say what's causing it.

Frustrating :-(

TheWildRover wrote:

...The same drives attached using a USB2 cable work perfectly. ... If I use a USB3 cable, then it all kicks off. Same drives, same enclosure, same adapter cards, the only constant that causes issues is USB3.

Cheers

Andy

I'm in the same situation. It's definitely either the USB3 cable or port for me. I have two LaCie Rugged external drives; One is connected using USB3 and the other is connected to the Thunderbolt port via Firewire and an adaptor. The USB device gives me the problem (and doesn't show up in LaCie Desktop Manager). When I swap the drives, the reverse happens. It's definitely USB or a cable problem. I'm lucky because I don't need to have both drives connected, only one. It shouldn't be happening though and as the HDD I rely on is 70% full, unless the problem is fixed I will need to either buy a new larger capacity drive (and discard my 12month old 1TB drive) or delete some of my iTunes library.

Holy mackerel! I don't know how you figured this all out but it seems to be working so far. Thank you! My external hard drives were ejecting on their own within seconds of me plugging them in. After doing your (seemingly) random steps, at least one of them is working now (my Time Machine). My other hard drive which is set up in a RAID configuration is still not showing up. I will contact Western Digital about that. (Unless you have some more tips!) I do have a question though- can I delete that SystemConfiguration folder from my desktop? It seems that it was only copied from the Preferences folder, not moved entirely. Thanks in advance!

Update:

My WD externally powered MyBook 1.5TB USB 3.0 drive simply would not stay connected under El Capitan, direct connect to the Macbook USB port or via the 3.0 USB Hub, no matter whether the computer was awake, sleep, just about anything except being actively written to.

Since this has never happened to my G-drive 1 TB Thunderbolt self powered drive, whether connected via TB or USB 3.0, I decided to get another G-Drive 1 TB, self-powered drive, using just USB 3.0, and to connect both G-drives via a USB 3.0 Hub, which will free up the TB port for other uses. After 5 days, not a single DNEP from either drive! Hope I haven't jinxed things with this post.

Anyone want to buy a WD 1.5 TB drive? Just don't use it with a Mac.

I have a 2012 iMac; when I first got it I bought an external Green Drive that kept ejecting when the computer slept. After much discussion with the manufacturer they agreed that they had a problem with their USB 3 hardware/software. I returned it and got a Lacie 1TB drive that has worked for three years with no problems; in fact I bought another 6 months ago. I haven't had the DNEP message during that time. However, after I updated to El Capitan, I now get it every morning when the computer starts up, on both drives. There is NO WAY this is not related to the update. I have checked and the "put drives to sleep" box is not checked. What's interesting is that rarely, maybe one morning out of ten, there aren't any messages. No problems accessing the drives after it starts up and all the data is fine; it's just the messages that are PITA. Would love to get some hints.

I have exactly the same. The problem relates to USB2/USB3 and Thunderbolt 2 drives. On the thunderbolt i need to remove the cable and reconnect it to get it to work (switch power on off on the front doesn't work).

Running a MacPro 6,1, with a LaCie 2BIG drive (which i can't use). The USB2 drives are just any thumb-drives.

I filed this morning again a bug report. I really hope Apple will do something about this! Drives me nuts!

The more people file this as a bug, the bigger change they will fix it.

https://bugreport.apple.com/

As I mentioned in my Oct 28 post above, this problem seems to be device-specific. I agree that El Capitan has worsened it for some drives. I had to get rid of my WD MyBook USB 3.0 drive--sold it. My two G-Drives, one a combo TB and USB 3.0. the other just USB 3.0, are working flawlessly under 3.0 with El Capitan 10.11.1--no DNEPs at all in a week with constant use, computer going to sleep, etc.

Hi Kev,

Thanks for the update. If its the h/w its most likely to be the controller (not the disk itself). The LaCie 2Big is one of the few TB2 (2nd gen) that was out there, so that that would not work with my MP (cylinder), is extremely weird. I think the MacPro (Cylinder) was one of the first withTB2 connectors.

What is the exact model you have?

I've got the G|Drive Mobile 1 TB 2874 and 3840 drives. They are both 7200, one of them TB and USB 3.0, the other just USB 3.0, but I'm running both of them on a Amazon Basics USB 3.0 (external power) hub into one rMBP USB port. Not a hint of DNEP with either of these drives. With my WD Drive and with a previous LaCie USB 3.0 drive I couldn't go for more than a day without a DNEP.

As you say, it must be in the controllers.

Its been 5 months since I last posted re my 6TB LaCie 2big Thunderbolt, running as Time Machine in a Raid set, having the DNE problem. While it almost always rebooted on computer / monitor startup, when it would DNE did not seem to set a consistent pattern. I have in touch with Apple and trying to isolate/identify the problem. I am still running Yosemite pending a determination whether the issue can be resolved soon in Yosemite. If not, I may reluctantly load El Capitan.

I have asked Apple support whether El Capitan (or any of its versions) is intended to address this issue, but the people I speak to don't know. We mere mortals aren't allowed to communicate directly with the engineers. Despite the number of people in various discussions raising the DNE issue under numerous OS versions over the years and with numerous hardware configurations, Apple support doesn't seem to have identified it as a prominent or important problem, and seems to consider it most likely an issue outside Apple's hard and soft ware, unless in individual cases a specific problem is noted in particular motherboards, ports, corrupted OS or permissions, etc.

The current stage I am at is testing connecting the iMac and accessories through a new APS surge protector. (Originally, everything was powered through an APS UPS unit. Then, to rule that out as the cause, I disconnected the UPS; the iMac was powered directly from the wall outlet; and the rest was powered through an old outlet bar plugged into the wall. The problem continued, so now we are up to the surge protector. For a day or so, no DNE. The next day a DNE with the LaCie nevertheless recognized. The next day a DNE with the LaCie not recognized. I had to unplug the Thunderbolt cable from the iMac and replug it, then restart. For several days, no DNE.)

Bottom line: I don't know much more. There is no obvious pattern except that sometimes somehow when I am away from the iMac the LaCie becomes dismounted and, within those sometimes, it sometimes remounts without my intervention.

Apple has not been able to explain to me what activities (when I am not using the iMac) could contribute to the dismount and to the failure to remount. When I send my contact in support copies of console reports around the time, it appears that these aren't read as only engineers look at and understand them and the support cadres aren't engineers. Frustrating, particularly where a Time Machine backup to protect the user is concerned.

I would have hoped by now Apple would have come up with an internal diagnostic to determine when and why external HDs dismount and when they "disappear." I know it is complex, but that is what Apple often does so well.

If I discover anything useful I'll pass it along.

PS - I am not heartened to hear that upgrades to El Capitan don't eliminate the problem or make it more manageable.

I have the same LaCie unit. I had the problems basically from day one (with a new MacPro!), basically what you describe. My feeling is it not getting better with El Capitan. I switched of mine, put it in a corner, since removing the cable to get it to work.....Grrr!! What do they think....?

Did you file a bug-report ? If not, please do so. I also offered Apple to work with them closely to solve this. Im pretty sure that its related to the driver card used in the LaCie, apparently G-Drive usages something else.

Im cleaning my unit, and its going back to LaCie, they will have a look at it. And lets see what happens. When di you buy it?

Obviously one of the biggest problems is thats it totally unclear if this a Apple or a LaCie problem.