External USB Hard Drive not showing up, after Yosemite update

I have read that if you turn Spotlight off you will have no problems. Open Spotlight, choose "privacy", click the "+" at the lower left and add what you do not Spotlight to search. Worked for me. I have 2 internal Seagates formatted OS X journaled in an external case. 🙂

Turning off Spotlight is not the solution. The first thing I did when I installed Yosemite was to turn off Spotlight -- which I've never* used -- on all permanently-mounted external drives. (Note that this was *before* I had any inkling that Finder and iTunes in Yosemite would randomly decide to not be able to see various of my external Thunderbolt/USB drives -- so far the problem hasn't afflicted any of my half-dozen or so external FW800 drives. Knock on wood.) Turning off Spotlight did not prevent the problem from occurring.

Also note that I do not know if this is a bug that was introduced in Yosemite since I upgraded directly from Snow Leopard to Yosemite. For all I know, the bug could have been introduced in any of Lion, Mountain Lion or Mavericks. (But it seems that most people posting comments on this thread are complaining that it started in Yosemite.)

* except for doing simple arithmetic, a feature that now no longer works in Yosemite.

I have a Western Digital My Passport and this method worked for me. Thank you very much indeed, I now have all my data back!

I ran Kext_Utility.app.v2.6.1

then restarted.

My USB Hard Drives showed up again.

Restarting always (so far) restores the ability of Yosemite to see previously-disappeared external drives (USB and/or Thunderbolt-to-eSATA), including two iPod Shuffles connected via USB. I've never had to run Kext_Utility.app or anything else to restore the normal functionality. Just a simple restart of the iMac.

Mid-2012 iMac.

well, lucky you. 🙂

And just to add more intrigue to the issue, my brother just reported to me that when he booted his Mac from an external Yosemite backup hard drive (made by SuperDuper!), Yosemite is unable to see the *internal* SATA hard drive in the Mac!!!! That makes it utterly impossible to restore a backup image onto an old or new internal SATA hard drive if you've booted the computer from an external Yosemite hard drive. So, instead of booting from an external Yosemite hard drive so he can restore a Mavericks backup onto the internal SATA hard drive, he had to boot from the external Mavericks hard drive so he could restore it onto his internal SATA hard drive.

Un-effing-believable.

Folks, I was having the same issue but solved in a very silly manner. I have a CalDigit FW800, Mac OS formatted external HD. All my itunes and iphoto files are all in it. After upgrading to yosemite the HD didn't show up in finder anymore, even though I could still use the files in iPhoto and in iTunes, and I could also see the HD in Disk Utility. Confusingly Finder did show a MS Windows formatted HD I also use. Well after juggling with it for a while I just tried Finder preferences. And there I just had to choose it to show any external HDs on side bar. Incredibly it worked. Oddly, this preference was somehow automatically unmarked while upgrading. Hope that helps anybody.

Hey guys. If you still haven't found a solution, I did this real quick.

http://www.pcdailytips.com/usb-external-hard-drive-not-showing-on-finder-but-on- disk-utility/

Basically running Disk Repair (this is for HD showing in Disk Utility but not in Finder).

Fixed my missing Toshiba hard drive issue in two minutes saving me a lot of sulking 🙂

Good luck.

Thanks, hello.cathy. What machine are you on? I ask because it seems that iMacs have a better success rate than MBPs. Your post brought back fond memories of when I tried this over and over again for about 30 minutes based on another post here from about two months ago.

I have an early 2011 MBP!

Here's some great news (if it also works for you):

MacBook Pro (15-inch, 2.53GHz, Mid 2009)

After my 1TB stopped showing up, I found suggestions from WD that it was either 1) an old hard drive or 2) the smartware didn't like Yosemite. They suggested avoiding an update and / or buying the USB Y-adapter 3.0.

I bought a USB Y-adapter 3.0 (one of the suggestions) - and while it didn't work at all on my MacBook Pro (15-inch, 2.53GHz, Mid 2009), it allowed the hard drive to be found on my PowerBook G4.

Here's how it's worked:

First, there was nothing on the G4 but then...

I ran the old reliable Alsoft Disk Warrior on the G4 - it found my malfunctioning 1TB hard-drive. I successfully rebuilt the directory (severely damaged, it said) - and now I have access to everything on the 1TB drive.

Warning - Later, after my success of saving my data, I tried putting the drive back on my MacBook Pro, it screwed everything up again. There's a clear Yosemite / WD something-ware issue. I've since restored it again using the above Disk Warrior rebuild.

I'm quite happy now -

This earlier suggestion from katzmannn worked for me too:

"clicked on the Finder, clicked on Preferences and under the General tab there's a section that says, "Show these items on the desktop," where I simply checked "External Drives." All is well now!"

It won't last. 😉

Hi,

I had the same issue and now have managed to fix it. Don't know if the issue is similar for everyone else, but thought of posting it in case it helps. Okie so I noticed the problem was with my USB 3.0 compatible HDDs whereas the USB 2.0's worked fine. A lil research on the internet also told me others were facing similar issues with USB 3.0.

Therefore I just went ahead and used a USB 2.0 HUB instead of directly connecting my HDD to my MBP and ...**bam** it worked. I presume you could also give it a try. If you have a USB2.0 hub or even an USB 2.0 cable extender/adapter, try connecting this as "middleman" instead of directly connecting to the MAC. Another friend of mine tried the same and it worked for him as well. Specifically with WD hard drives. Have not tried on others.

Well best of luck!!!