Anyone else having problems with external disks unmounting randomly/suddenly on Mavericks?

Well, for whatever reason, the LaCie drive is now working. It gave me some funky error messages when I tried to use Disk Utility to Erase it and rename. I formatted as:

Mac OS Extended (Journaled, Encrypted)

I'm using a Thunderbolt connection from my Mac Book Air to the LaCie drive.

Everything seems to be working now. Time Machine kicks in every 60 min.

Strange....it shouldn't be this difficult.

I never experienced this issue on my Late 2009 iMac 3.06ghz Core 2 Duo using 4 drives hooked up via USB 2.0 hub. 2 of the drives are Seagate USB 3.0 drives and one WD MyBook 650gb, and another WD 1TB drive.

I Just bought a refurbished 27" iMac late 2013 model and seem to be getting this unmounting issue on both the WD drives which are still hooked up via the HUB as well as the 2 seagate drives which are now hooked up directly.

I'm afraid of losing the data after reading this thread. Currently i have my drives hooked up to my older late 2009 iMac as I'm backing things up before formatting it. Same set up with the 2 seagate drives hooked up directly and the other 2 drives via the hub. Nothing has unmounted - as it hasn't in the past.

Both computers are running Mavericks 10.9.1

the only difference I can be sure of is that the newer iMac has this update installed

"iMac SMC Firmware Update Version 1.1" Which states its for imacs late 2013 with flash-only storage. My iMac has the Fusion drive, but not a flash drive installed.

I turned off the option to put harddives to sleep a few days ago as I run a plex media server from my mac and I don't want it to go to sleep or turn off when I'm randomly attempting to watch movies/tv shows from another room.

I'd like to say that it's more of a hardware issue than Mavericks, but after scanning through these posts it seems like a wide range of hardware. But not sure why I don't have the issue on my older iMac but the issue annoyingly exists on my brand new(ly refurbished) $2000 machine. I've been trying to back up my important files to offsite storage, which in the short run is cheaper than buying new drives, but over time that montly cost will add up. I'm hoping that I can continue to successfully upload everything before mavericks destroys my drives and/or data.

Update: I posted before about my Thunderbolt Drobo that gives me trouble with the "did not eject disk properly" dialog after sleep as well as the drive not showing up on the desktop occasionally on boot. It all started like everyone else on the day I upgraded to 10.9. I know many have had problems with USB drives and cables. I realized that my Thunderbolt cable was a 3rd party cable and figured I had nothing to lose so picked up an Apple Thunderbolt cable and swapped it out. Well one full day later and 2 restarts/ 5 sleeps... no errors.. will update if that changes

I've also a 27 inch iMac (late 2013) with a fusion drive. Same problems with external HD before and after the "iMac SMC Firmware" update. So, that's not the problem 😟

Well at least that answers that part of my concern. I thought my issue may have come from the fact I bought my computer refurbished - however after finding this thread I can see its not just me. I don't have anything go to sleep except for my monitor, and when i come back from waking the monitor is when I normally see the disconnect/unmounting messages.

I have been having this exact same issue for about two years on random occasions with the same external drive. I can't say which OS it started with because it was rare and random, but definitely since Snow Leopard on my MacBook Pro, early 2008 model. But in the last year, and especially since upgrading to Mavericks, it has been a serious problem. I have an NTFS partition on it and an OS X partition on it. Back when I used to have the partition journaled, after about a few weeks of it ejecting the drive on its own, the partition would fail to mount. NOTHING I could do in OS X would repair it or allow me access to my data. Ironically, I could download MacDrive for Windows, boot to Windows and repair it in MacDrive and boot back to OS X and it would mount and read again just fine. That's a very very sad commentary for Apple.

Since then, it's failed a few times where I couldn't mount or repair it, but I was able to mount it on a Linux machine just fine and copy all my data off from it then reformat it and it's been just fine. I never get errors, I can run various diskchecks utilities on it that find absolutely no problems with the drive, but after repeated unmounts because my computer went to sleep, it ultimately will cause it to get an error that forces me to hook the drive up to Windows or Linux to save the data. I can have Windows or Linux on the very same machine and the drive reads just fine, so it's not the drive or the controller. It's this repeated forced dismount causing some type of corruption that eventually OS X just won't handle. But there is NO reason that OS X Disk Utility shouldn't repair it if I can fix it with WINDOWS!!! There's no reason that command line repairs won't fix it either if I can fix it with Linux since OS X is Unix. It's very frustrating.

But I have found that keeping the drive unjournaled and DEFINITELY not case-sensitive will keep it from failing so much. It's ironic that unjournaled is better, since the whole point of journaled is to give the system a second way to locate the files. But it just gives up if the journal gets corrupted. I absolutely love Apple and everything about my Mac, and most everything about OS X. But this thread alone is 8 pages long, and there is not a single response from Apple about this. I have found several other threads about this exact same problem, so it's not just random, and it's not just failing hardware. It is a problem with the OS. And I'm really bothered that they aren't addressing it, because I was lucky that I haven't lost data. I backup like crazy, but when Windows saves your Mac data because OS X can't, you know there's a serious problem.

Thanks PlotinusVeritas, removing the drives from the spotlight preferences worked for me.

I just got a new IMAC and experienced the same issue with a RAID 10 array with 4 drives spontaneously disconnecting in the middle of a data transfer with the message "you should eject disk properly, etc. etc." message.

As many others I tried all the obvious solutions. Different cables, different drives, etc. Then I read something about radio wave interference from wireless keyboards. Well, I don't have wireless keyboards or mice (don't like them) but still, it stuck in the back of my mind.

I did find that a USB 2.0 cable with noise suppression dongles at each end worked just fine, if a bit slowly. Anyway, I found an old set of ferrite couplings that were made for video cables back in the day and placed one set at each end of the USB 3 cable. I then moved my RAID array as far from the computer as possible and plugged it all back in. The problem has not reoccurred even with the transfer of very large folders of files from a networked PC RAID.

Just a thought but it seems to have worked for me although the fact that this sort of thing is necessary does not speak well for Apple.

One month later update...

Since I changed my USB 3 cable I have not had a single issue..

I agree... How can a standardized cable be the problem

One month later as well...

2nd update: My problem was a Drobo Thunderbolt that gave me trouble with the "did not eject disk properly" dialog after sleep as well as the drive not showing up on the desktop occasionally on boot. I too have not had a single issue since swapping out my aftermarket Thunderbolt cable for the Apple Thunderbolt cable. I can't speak for USB 3 cable internals, but I do know they can deliver more power to an attached device (900mA)...but USB 2 cables . USB 3 also handles idle, sleep, and suspend states differently than USB 2. Thunderbolt cables have chipsets in the cable and the Mac hardware/Mac OS are very peticuliar to what cable you use.

Hello,

Has anyone already tested with new Mavericks 10.9.2 update? Is USB 3.0 issue with unexpected unmount HDD external drives still occure?

Hope I could clean from dust my 2xHDD bay from shelf and connect to iMac for backups.

Regards.

I do agree on this theory:

https://discussions.apple.com/thread/5611308?answerId=24050472022#24050472022

Would be interesting to know what hard drive models resp. enclosures people with this problem are using. Maybe they all have a certain controller chip in common? Of course not anyone wants to take a look into the enclosure, but one for each model should be sufficient.

Starting a new discussion here, feel free to contribute with your failing drive:

https://discussions.apple.com/thread/5943136

Thanks!

Just to chime in, I was having the same issue on my Late 2013 27" iMac, OS X 10.9, 1TB Fusion. It didn't matter if it was an external HDD, an externa SSD (in a dock or its own enclosure) or a thumb drive, USB 2.0 or USB 3.0. They would randomly and without provocation (movement, etc.) eject with the warning notice. AFAIK none of the drive's themselves or their content was corrupted as they are still working.

I reinstalled 10.9, reset the SMC and PRAM several times. Things seemed to improve for a while, but after a few days the problem returned.

I ended up taking it to the Apple store. They ran some bench tests and everything passed. They kept it for a couple of days, called and said that they could not reproduce the problem. I asked them to wipe the drive and reinstall OS X 10.9 which they did. I manually reinstalled my apps and copied over my content (documents, etc.) rather than restoring from my Time Machine backup.

It's been a little over a week now and the problem has not returned.

Unfortunately I did not check the Boot ROM/SMC versions prior to taking it into Apple so they may have updated that. I think it was posted previously, but here's the link to check to see if yours is current:

http://support.apple.com/kb/ht1237

After reading through this and a number of other threads I can take some solace knowing that it's not "just me". I updated to 10.9.2 yesterday and things still seem to be working okay. Fingers crossed that this issue has been addressed but I will stay tuned.

I bought an ANKER USB 3.0 4-Slot USB Hub and this seemed to increase the frequency of the issue for me. I have yet to have any corrupt data (yet), however I moved my drives back over to my older Belkin USB 2.0 7-Slot Powered USB hub and haven't experienced the issue. Just ***** to lose that 3.0 speed, but if it protects my data and alieviates the issues, I guess it will work for now. Though I haven't tried reconnecting the drives directly to the iMac or Anker hub since the update I applied yesterday. I'll give that a try for the next few days and see if the errors pop up again.

This is beyond annoying. I have an external drive connected directly to USB port and another connected via USB 3.0 hub, and both eject themselves randomly and frequently. Sometimes I also have old Firewire 800 Drives connected thru a Thunderbird to Firewire 800 adapter and those have never been ejected. Not sure what that proves though.

Where is Steve Jobs?