Hard Drive won't mount in Yosemite

I suggest you contact the drive manufacturer. It sounds suspiciously like they need to update their software.

Barry

I have 2 Seagate hard drives formatted mac os extended journaled also. 1 is 750 GB and the other is 1 TB. Worked awesome in Mavericks. Now in Yosemite, not so much. They are not visible in Disk Utility but after hot plugging with USB 3.0 then waiting around 10 minutes they show up. I run "verify Disk" and they are now accessible to view in Disk Utility but not access the contents. I can see them in Finder but there are 0 folders. After another 10 minutes, the folders show up but I cannot open them to drill down to their contents. After another 10 minutes I can finally see all of the files for....go ahead guess.....10 minute then suddenly I receive a pop up that say the drives were ejected improperly and they are gone.

I'm thinking of going to an authorized Apple repair place to see if they can be hot plugged on another Mac and viewed in Finder.

Hopefully I can save the 300 GB of backup I have on one of the drives.

Any and all suggestions are welcome

iPhoto won't pull in photos from my digital SLR. i have a feeling they overhauled something with the USB's "brain".

No one responded to my community support post. I'm glad it "woke up" for you.

I have exact same problem, also with a Seagate drive (new 4tb portable). Takes hours to appear. Did you find a solution!

Status Update...After reading other threads in regards to this issue, some have suggested to download the Paragon NTFS driver from the Seagate site. I did that and my drives are visible. BUT, it still took 10-20 minutes to get all the folders and subfolders to open. Once open, I tried to move a file from my internal SSD drive to the external drive. Previously it would not work. It would time out with a message "error code -36" which I have not been able to get an exact answer what it is. After installing the Paragon NTFS driver, and seeing the external drives, I again attempted to transfer a file to the external drive.

The 1.9GB file took 40 minutes to transfer. Once transferred, it would NOT open from the external drive.

It seems there is a communication problem through the USB ports. Yosemite update bug to the 100X.

I have the same problem with my external USB hard drive. It is the Western Digital "My Passport" Edge for Mac model. I updated the external HD driver from WD's website, but still no luck. The external drive shows up in Disk Utility but is not recognized by Finder, thus, Time Machine and other back-ups won't run.

Please help. Thanks.

I have this problem as well unfortunately. Since I upgraded to Yosemite my Freecom external drive has shown erratically in Finder but is now completely absent. It does show in Disc Utilities but asked me to repair it. When I tried to do this it reported that it couldn't be repaired. Immediate panic because my thousands of photos are stored on the drive. However, I have now plugged it into another Macbook Pro running Mavericks and it appears to be working perfectly!

I have been happy with Yosemite apart from this but it looks as though I will be trying to revert to Mavericks.

Hi, I spoke to Western Digital support and they believe the Yosemite update did something to the drive. Interestingly, I have two identical My Book Studio II drives and one was not connected during the upgrade and it is fine. Western Digital could not help fix the problem but to offer me free data recovery software and reformat the drive. It sure seems like this is an Apple issue. I'd be curious if anyone has found a fix yet....

Okay, I followed r3xsy's instructions (downloaded and installed the NTFS driver from Seagate). Then I unplugged all of my USB devices. Unplugged the mac from the wall. Plugged in the Mac to the wall then started. Then unplugged my external from its power source. Replugged in the external into the wall then plugged into the Mac. SO far, it is working, even after sleep and awakening. ONE ISSUE...I cannot copy a file from my Mac drive (SSD) to the external drive.

I had an even weirder problem today. I installed a Samsung 840 Pro SSD in a client's MacBook Pro 2011, Core i7, 750GB. Prior to that, I had installed Yosemite on the SSD & made an admin user. Using my SATA/ USB 2.0 (powered) adaptor kit, the HD I removed was *not recognized by Yosemite - in the very MacBook I just removed it from! Also would not mount or be recognized on my 2 other Macs, both running Yosemite 10.10!

Luckily, I had made a time machine backup to a brand-new OWC Firewire HD, which I was able to migrate user, data & apps from, onto the new SSD.

The old HD is a Toshiba/ Apple 750GB, 5400RPM.

The only conclusion I can come up with is Yosemite 10.10 does not recognize a (bootable) HDD with Lion 10.7.5.(?!?)

I've never seen this kind of behavior before on *any version of OS X.

Any thoughts, besides "thank god for time machine"?

Strange...

I agree with John Swords assessment. My WD Passport Edge for Mac was plugged in to my USB port during the update to Yosemite. After the upgrade was completed. I could no longer access the drive. I have subsequently purchased a new WD My Passport for Mac (1 TB) and it connects fine on the Yosemite OS and I am back to using the drive as before. I am suspicious that something during the Yosemite install/upgrade process killed my WD external HD. RNaj

I did everything right, formatting my 2T WD Passport to "journal" etc. at the same time I was upgrading both my MacPro and my iMac to Yosemite. So, I was sort of in-between OS.

At first, it worked fine. But the last Yosemite upgrade or patch or whatever blotted it out entirely. Can't find it anywhere or anyway and now I know I'm not the only one having this trouble.

I'm lucky-- I will lose no data if I reformat "in Yosemite as of 11/20/2014" and put all the data* I was saving on a second time, (although I wonder what would happen if Yosemite again mutates.)

*All I was doing was making a sort of backup and second drive for my laptop, so the data is all on my laptop.

Is the general consensus that WD peripheral hard drives DO work when set up as Mac journal in Yosemite? Or are solutions still inconsistent?

Am pretty sure I've seen WD Passports for sale in my Apple store. Please keep me in the loop-- this is actually my first day in the support forum and I'm troubled because I've found a lot of people are reporting similar problems,

My seagate external being used with time machine was working fine as back up. Used it to back up my data before upgrading to Yosemite but now it is not recognized/ being mounted so what good is backing up data if my IMAC won't access the backup drive now?? This is a major dilemna for apple...unless they are simply trying to get people to buy their TIME CAPSULE! Won't be the first time a company did this.

It's a bigger issue than hard drives. I lost the ability to connect my GoPro cameras with USB.