External USB Drives Not Mounting on Wake From Sleep on new iMac Pro

Angelo,

Thank you for taking the time to respond.

The very first thing I did when I received my iMac Pro over a week ago was to go to System Preferences>Energy Saving, and uncheck the box beside the option to "put drives to sleep when possible". I have even gone in and checked and unchecked that option again, but unfortunately this did not have any impact on the issue of my two Western Digital external hard drives ejecting during a wake from sleep and not mounting requiring either a restart of the iMac Pro or unplugging and plugging back in the hard drives.

To end on a positive note, I have been working quite a bit to remove unneeded applications that launch when I start up my iMac Pro, and when I put me iMac Pro to sleep last night and woke it up this morning, all of my drives were mounted and working properly. Furthermore, after putting the iMac Pro to sleep for three more hours today, upon waking it all of the external hard drives are mounted and working properly. I am not ready to declare the problem solved, but I am more optimistic than I have been.

Tom

I wanted to make a final post to this thread (started on December 30, 2017) three days after I received my new iMac Pro and discovered that all USB drives (of any type and brand) connected to the iMac Pro would immediately eject upon waking from sleep.

After working with several Apple Senior Advisors for more than six weeks, I am pleased to say that this issue has been solved. It was solved by removing a file (Pegasus2R2ICON.kext) from the systems library and placing it in the trash. This is one of two files installed by the driver download for the new Pegasus3 R6 raid 5 array that I purchased at the same time as my iMac Pro and installed on the thunderbolt 3 port. The driver, downloaded directly from the Promise site, is the correct one, but this file (which appears to serve no purpose since the Pegasus3 works fine with that file removed) is directly responsible for the immediate ejection of all external USB drives attached to the iMac Pro. I have never had a single ejection of the external USB drives since removing this file more than 14 days ago. Restoring this file and rebooting, then putting the iMac Pro to sleep and waking it in an hour or so produces an immediate ejection of the external USB hard drives.

Thus, the problem was related to the specific configuration of my iMac Pro (which has a Western Digital thunderbolt 2 My Book hard drive, a Pegasus3 thunderbolt 3 R6 raid array, and two WesternDigital USB 3 hard drives attached to its ports. Had I not had any USB drives attached to the iMac Pro I would never have seen the drive ejection issue even with the Pegasus3 attached. When I had external hard drives attached to the iMac Pro but no Pegasus3 on the iMac Pro, I never had a drive ejection problem. When I have the Pegasus 3 R6 array attached to the iMac Pro, but I remove the Pegasus2R2ICON.kext file and place it in the trash, I have no ejection of the external hard drives, and I see no deleterious results on the performance or operation of the Pegasus3 R6.

I have also observed and reported in the Bootcamp Apple forums that attachment of the Pegasus3 R6 to my iMac Pro results in my being unable to boot into Windows 10 (installed under Bootcamp). If I remove the Pegasus3 from the iMac Pro, I can boot every time into Windows 10 with no issues. I have notified and I am working with Promise Technology on these two issues produced by the Pegasus3 attached to an iMac Pro, but to date no resolution of the issue of being unable to boot into Windows 10 with the Pegasus3 attached has been forthcoming from Promise Support.

Tom

I really appreciate your taking the time to explore this issue with your iMac Pro. Thank you for doing so.

I don't think it is an issue with the hard drives since both are behaving the same way, i.e. failing to mount on a wake from sleep and both external hard drives were snot showing this behavior on my mid-2012 MacBook Pro to which they were attached. I continue to explore this problem, and report any new results that I find. Thanks again.

My energy settings are the same as yours. I do not have our hard drives to sleep checked. In fact, I have checked and then unchecked that to see if it made any difference. It did not. Both of these external hard drives are connected to the type-A USB ports on the rear of my iMac Pro. One possibility is that my Pegasus3 R6 raid takes a few seconds to come on upon wake from sleep, but I don't see how this could impact the USB 3 ports on the iMac Pro. For now it represents an irritating mystery.

Tom

Just an update to say that the issue with my two external USB3 drives not mounting on wake from sleep has apparently been resolved. I did a PRAM reset and I have not had the external hard fail to mount since doing so. Love this iMac Pro!

Tom

Unfortunately after more than a week of working with my iMac Pro the problem of my two external WD USB3 HD's not mounting upon wake from sleep has never been resolved. I have been in touch with three different Apple Support individuals. One of them told me it was a Western Digital problem and there was nothing Apple could do. Needless to say, I did not agree with that since when I start the iMac Pro up cold or do a restart the two hard drives always mount, and I never have an issue with the drives unmounting until I put the computer to sleep for an hour or more and then wake it up. Several times I thought I had solved the issue with a PRAM reset and an SMC reset, but in both cases the external hard drives mounted once when I woke the computer from sleep and then after that the same old problem of not showing up after waking it from sleep reoccurred. I escalated the problem in Apple Support and I am still hopeful that eventually they will come up with a solution.

Tom

Just wanted to post an update. My iMac Pro has continued to frequently not mount my two Western Digital USB3 hard drives. Three days ago I worked for several hours over three phone calls with a senior Apple Supprt person. We removed every item in my list of programs loading on startup. That did not resolve the problem. We then removed several items from User>Library >Launch Daemons, System Library>Launch. Agents, and a few ktext files that he felt could be causing the problem. The drives still continue to not mount after the iMac Pro wakes from sleep about 75% of the time, and of course the iMac Pro was basically useless with these files removed. The Senior Advisor was to call me back, and further work to restore the files that had been removed but has never done so. That was 4 days ago. I have now restored the essential files to their proper place in order to be able to use this $9,000 computer for useful work. The iMac Pro runs all apps fine, but still dismounts. My two external USB3 HDs about 75% of the time upon wake from sleep.

I have now removed the older of the current two external USB3 drives and replaced it with a newly purchased WD My Passport bus-powered USB3 HD. If that does not solve this issue, I will remove the other WD USB3 HD, leaving only the bus-powered USB3 HD in place. I’ll report back in a few days whether this solved the dismount issues or not.

Tom

Since my last post I have (1) purchased and plugged into the iMac Pro a new Western Digital My Passport 4TB bus-powered USB HD. With only this new HD installed more than 75% of the time when I wake the iMac Pro from sleep, I get the ”drives not ejected properly” and the HD Is not mounted. (2) I then replaced the WD hard drive with an Orico external enclosure containing a 1 TB HD and a USB interface. With that USB3 HD plugged into the USB3 port of the iMac Pro I also got the same message and the HD was not mounted on waking the iMac Pro from sleep. I have done an SMC reset and a NVRAM reset. These did not solve the problem. I have reinstalled Mac OS High Sierra, and that did not remove the problem. I have contacted Apple Support 4 times regarding the USB3 issue. At the request of an Apple Senior Advisor I prepared and submitted a full system diagnostic using software provided by the Advisor and that has been submitted to the Apple Engineering Team.

At this point I have exhausted all solutions that have been provided or can imagine. In as much as the USB3 ports on my iMac Pro are dysfunctional, I have removed all USB devices from the iMac Pro and I am using only Thunderbolt3 and Thunderbolt 2 external hard drives. There appears to be no problems with Thunderbolt hard drives on waking the iMac Pro from sleep.

i am very disappointed that on this very expensive iMac Pro I cannot use any USB3 external HD.

Tom

Hi Kevin,

Thank you for taking the time to respond. I appreciate your making the effort to share your experience with me.

I have spent a lot of time on Google researching this problem, and indeed I can find that ejecting external USB drives is a common Apple problem, although I have five other Macs including a fully maxed out Late 2013 Mac Pro and none of them have ever exhibited the issue of ejecting USB drives on waking from sleep. I have confirmed that dismounting the USB drives on this iMac Pro happens consistently and 90% of the time on wake from sleep even for USB2 hard drives and USB2 and USB3 flash drives. In addition, I am fairly certain that the problem with the USB ports on my iMac Pro is associated with my inability to boot into Windows 10 (installed using Bootcamp Assistant) with any external USB hard drives attached. The iMac pro simply hangs at the Windows logo screen and spinning white circle of dots and never boots. If I remove the external USB hard drives, the iMac Pro will boot into Windows 10 every time with no problems.

I have been in contact with four different Apple Support staff regarding these two problems and I still have an open case. Two of these four Apple Support persons are Senior Apple Advisors. One of them simply stopped communicating with me regarding the problem even after promising to call me back in order to repair a lot of library and system files that he had me remove while trying to solve the two issues. The second Apple Senior Advisor communicated well with me for a week, and now he, too, has simply disappeared. He was supposedly working with an Apple engineering team on the problem, but other than asking me additional questions which I gladly answered in the hopes of solving the problems, I have received no useful suggestions that have helped with either problem.

I believe this is a hardware problem with my specific iMac Pro (since no other iMac Pro owners on the Apple Forums are reporting this problem and two have assured me they do not have the problem). I identified the problem the day after receiving my iMac Pro (December 26th) and filed a formal case with Apple Support on January 2, 2018. This case remains open and active. I have asked for a replacement iMac Pro configured as this one is and I have even offered to have Apple put a charge on my credit card to enable an advance placement of a new iMac Pro to be sent to me. To date I have not been successful in convincing Apple Support to take this course of action.

The bottom line is that I have had a dysfunctional iMac Pro (approximately $9,000) for more than three weeks with no sign of any resolution of the two issues I have described. I am very disappointed with Apple regarding the support that I have received on these problems.

Tom

Thank you very much for posting this abstract from a discussion on the Apple Development Forums.

I followed the directions carefully and completed the entire procedure. Unfortunately, these changes did not resolve either of the two issues (USB external drives ejecting on wake from sleep or being unable to boot into Windows 10 with any external USB drives attached to my iMac Pro)

I was not surprised since upon reading the entire discussion in the thread this procedure seems to be addressing an issue wherein USB drives are not being mounted on booting the Mac. That is not my problem at all. All of my USB external drives are always mounted when I boot up my iMac Pro or when I eject, unplug, and plug them in again. However they are ejected 95% of the time upon waking my iMac Pro from sleep. That and my inability to boot the iMac Pro into Windows 10 with external drives connected are my two issues. I believe these two issues are related, but I do not have direct evidence of that.

Thank you again.

Tom