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

Richsadams,

So just to confirm, you told the setup assistant to transfer "users" and "settings", but not "applications" and "other files..."

Then you reinstalled all of the 3rd party software after that.

That about sum it up?

Thanks,

Bart

Hi Bart,

I had them completely wipe the Fusion drives ("scrape and pave"), taking the machine back to factory/as-new settings allowing me to start fresh.

Cheers!

So I've finally got all my data off the drive by blowing a fan on it at high to keep it mounted for intervals of 20 minutes. After that i reformated the drive to FAT32 via Mavericks and so far it has stayed mounted. Copying all the data back over now. I'll let u know if it again disconnects at some point.

This is a nightmare. Same problem on my MPB (10.9.2) which I got delivered in February. I got two extrenal drives: 1 x LaCie Rugged..something and 1 x Seagate..something. I've tested two different USB3 hubs. Connecting an extra monitor to a thunderbolt port frequently causing the wifi to shut down, my external drives are frequently ejected.... what can I say. Brilliant!

Here's my story: New rMBP 10.9.2, migrated from MBP 10.6.8.

WD My Book USB 3.0 worked flawlessly until it was switched over to the rMBP--it just would NOT mount!

I then connected the WD (USB 3.0) through a USB 2.0 hub--worked flawlessly! Unmounted the drive, took the hub out and plugged it direct--now it works! Restarted once and it still mounted. Though it says this when I verify disk with Disk Utility: Partition map check failed because no slices were found. WTH does that mean?

Did that fix it? I don't know...

Now, the intermittent network connection thru the thunderbolt-ethernet adapter (but perfect thru wifi)? That's another (horror) story entirely...

How many user have google drive installed,i worked back as this has just started on my mac 27.Tried all fixes in this post to no avail.Was pulling my hair out as i just could not solve the issue.

uninstalled google drive two days ago and so far drive is working perfectly.

May be worth a try its certainly fixed my problem.

I've also been having this problem, on my late 2013 27" iMac. Started a couple of days ago. I'm sure I've had this issue before, more than a year ago, with my old 2009 MacBook Pro, probably running Lion or earlier. A good chance it was the same drive (WD 3TB Green in a Vantec NexStar CX enclosure). Not sure how I resolved it. Might have simply "fixed itself".

When it happens, I reboot and then it seems to be OK. I don't think it's related to sleep for me, since the last time it happened was soon after booting up and less than several minuets after mounting and using the drive. I do shutdown with the option to re-open windows/apps checked.

The only big changes I've made to my system in the last week have been connecting my old 24" Apple LED Cinema Display that I used with my old MacBook Pro. And I've installed Parallels.

With the old MacBook Pro, I connected the drive via the USB hub on the Cinema Display. Now, I have the drive connected directly to the iMac. I have the Cinema Display connected via USB so that I can use the brightness controls, but don't have anything plugged into its hub.

If it keeps happening, I’ll disconnect the Cinema Display from the USB and see if that helps.

Disconnected the display and it's still happening.

Hi, I was having the same trouble after the latest Maverick update, finished up downloading and installing the Maverick Combo update Computer has been fine since keeping my fingers crossed as I seem to have no end of trouble with Maverick and I have a good mind to go back to Snow Leopard.

Kind Regards.

Adrian Vogel.

I've been having the same issue with my Seagate GoFlex drive that was connected to my MBP via the Thunderbolt interface.  I replaced the cable a few days ago and I haven't had the drive unmounting unexpectedly issue since.  The original cable was one I had bought at Walmart.  This time I bought the Apple cable. 

Ed  

I had the same problem with Time Machine and solved it by enabling "Enable Power Nap" in Energy Saver:

System Preferences...

Energy Saver

Restore Defaults

Check "Enable Power Nap: While sleeping, your Mac can back up using Time Machine and periodically check for new email, calendar, and other iCloud updates."

2013 21.5 iMac

OSX Mavericks

Seagate 1 TB slim USB 3.0 (power is drawn from USB port), formatted to Mac Journaling File System

Dr Bear - i have same situation and model, new hard drive with new fresh install of mavericks - still disconnecting after 24 hrs of ok backing up - untouched. APPLE'S silence on this most popular concern strikes me that they must recognise a failure of their system. lets hope a new update finds and gets rid of a bug. but no word from them is appalling.

i meant external hard drive disconnecting.

Guys,  I don't think this is a Mavericks Issue.  I have been having problems with external USB and Firewire drives ejecting with my old 27" iMac running Lion for a long time.  My back up drive and two others have been destroyed so far from constantly being corrupted by the random ejections.  My iMac internal drive has also been corrupted to the point that it is impossible to reinstall the OS.

About two weeks ago I bought a brand new MacBookPro with Mavericks installed.  It has the same problem.  I have tried about 6 different powered USB hubs including a 7 port hub with a 3.5 Amp AC adaptor but it makes no difference.  As long as there are no more than two external drives it doesn't happen often but still often enough to keep corrupting my backup drives.  If I plug in a third drive one of the others will usually immediately eject.  It makes no difference if they are all plugged directly into the ports at the back of the iMac or into the powered hub.

My drives are various makes, mostly Imation but some La Cie and one WD.  The WD ejects the most often.

I was told there is an application that solves the problem but I don't yet know what it is.

i don't think your iMac running Lion creating a similar problem removes Mavericks from the equation. i have had my macbook pro form 2010 running Snow Leopard with no hitches whatsoever until i installed Mavericks and it corrupted 3 drives i've had no previous issues with