External USB Hard Drive not showing up, after Yosemite update

This worked perfectly for me and my three external WD disks - thanks! 🙂

I had the same problem...but the external hard drive was formatted for both windows and apple. I plugged drive into window tablet...it showed up ...ejected it then plugged back into mac...showed up fine then...
I think that something may have happened to the boot info...jmo

Hi everybody,

One year later and still no solution? I am having trouble with a single TDK 16GB pen drive on a new rMBP (early 2015). Machine has one USB 3.0 Hi-Speed port and one USB 3.0 SuperSpeed port, but the drive won't show up, neither in the Desktop nor in Disk Utility nor in System Report.

The weird thing is that I can use it just fine in another machine, which is also using Yosemite (2011 MBP). I've been using that second computer as control for trying out various format and partition configurations to make it work on the rMBP: when the drive has been freshly formatted/verified/repaired it shows up just fine on the rMBP, but as soon as I eject it and plug it back in, it never shows up again. (I've tried both Mac OS Extended Journaled formats, FAT32, exFAT, both as GUID and as MBR, to no avail). It all started when trying to transfer some files from the old MBP to the new rMBP using the pen drive and I've been stuck in this loop all day long.

From this thread and others, and despite many users going for third party software or looking for updated drivers from their own drives' manufacturers, I gather that this is strictly an issue with Yosemite, that has affects many users on many levels. Why then hasn't Apple taken care of it?

Hey guys, I have a temporary solution. Just restart your Mac then the external hard drive shows up in Finder. I'm using early 2015 MBP, Yosemite 10.10.4. Hope this method helps!

Also, I don't know for sure if it's the same issue described here, but if you read this thread (Hard Drive won't mount in Yosemite), many people report that the Yosemite update did something to their drives. As RickRockUSC suggested, my drive worked when restarting the computer, but that is no solution in my case as I need to swap the pen drive back and forth.

Any other recent cases?

Yes, still fighting this problem on a brand new Mac Book Pro 2015. I had a Lexar 128GB USB3.0 drive with my Itunes library on it, formatted FAT32. The Mac Book read it fine for months, now it does not. Every other machine I plug it into reads it just fine.

I have wasted an inordinate amount of time researching and trying to get the Mac Book Pro to read various USB drives.

Something so simple Apple completely botched and has never bothered to address.

I've got a 2TB Fantom USB 2.0 drive that I've had for a while, its my quick storage drive for many graphics files that I really need to get to. This drive has been a rock for me and I've never had any issues with it. It shows up in both Disk Utility and in Terminal using the diskutil list, so the iMac knows its there. Its not showing up in Finder however, and thats whats driving me nuts. In Disk Utility I see the drive listed and immediately below and indented I see disk1s1 which is grey out. I tried "First Aid" and it goes through a short checking sequence then a line comes up saying "Problems were encountered during repair of the partition map" and under that in red "Error: Partition map check failed because no slices were found."

I can select "Restore" from the upper menu for dsk1s1 and it lists a Source, and in that line is a greyed dsk1s1, and below is a "destination: but I'm unsure if I should proceed. I have already tried re-starting my iMac, powering down and un-connecting then re-connecting the USB drive... nothing seems to do anything. This happened about 2 days go, and I'm sure that when I re-booted one time I saw the drive in Finder, but then it went away.

I really need to get at those graphics files, many of which are Adobe PSD and AI files, plus tons of images from clients. If anyone can shed a little light on what I can or should do, I would appreciate it greatly.

Mike

Kext Utility fixes the problem for me. Thanks!

Yosemite 10.10.5

MacBook Air mid-2013

Old Lacie Rikiki 1TB

I can also write to the NTFS disk by putting:

LABEL=Rikiki none ntfs rw,auto,nobrowse

in /etc/fstab

This is a BUG ... serious Bug ... affect HFS+, NTFS, ExFat, FAT32, etc ... in USB 2.0, USB 3.0 or Firewire 400 ... I don't know if affect Thunderbird or firewire 800.

I'm struggling with this problem a few days.
I was in NTFS and the external disk disappeared in USB and Firewire and then later in the disk utility came with the same message that all narrated.
I reformatted to HFS +, I put the firewire and was stable for a few days. Did the Yosemite updates and external disks disappeared and never came back .. in fact ... come back and present the problems narrated on the disk utility.
I took to the Windows PC and installed the Apple HFS Driver (http://www.markc.me.uk/WebSiteDownloads/AppleHFS.zip / has the apple also comes with the boot camp) ... and miraculously the files are all there and reading is completely normal and stable.
Only difference: drivers!
It's time we take the apple to the courts. Use her products for over 25 years ... since the first macintosh and I've never seen so irresponsibly as I see to read all the posts ... they did not give any answers to provide.
Best Regards.

Updated to El Capitan, then was unable to access backups on Time machine on my Macbook Air and Mac Mini. Luckily I had a recent back up of documents on a 2TB WD My Passport Ultra, plugged into both machines and it does not appear in finder.

Disk Utility stalls with the revolving wheel looking for anything.

Losing my faith in Apple

November 3 2015, have just done a WD utilities update, restarted macbook pro and all is working again

do you have the link to the update?

Ok, this may help some, hopefully most.

External Drives: Toshiba Portable Hard Drive 1 TB PC+ Mac, Buffalo 2TB, Seagate 2TB

OSX: Maverick

Macbook Pro13-mid 2012

Problem: Mac freezes and Hangs and Refuses to boot

Action: After countless hours and attempts of self help from Apple Troubleshooting....final option= RE-Install OSX

After Reinstalled OSX, ALL external drives did not show on Finder but only on Disk Utilities and could NOT be verified nor repaired.

Did EVERYTHING this forum suggested by many good members here..still NO help. Kext Utility and OnyX did NOT work.

Finally, after almost 8 frustrating and exhaustive hours, stumbled upon ONE godsend site online and tried this one option:

Installed Tuxera.

Viola ! ALL my drives appeared on Finder.

I can't remember if I rebooted after installing Tuxera because I was so freaking tired-up whole night from midnight to 10am next morning, but no harm rebooting just in case.

Hope this helps some of you if not most. Good luck! 🙂

Link to download this very PRECIOUS Tuxera:

http://appledigg.com/t/free-download-tuxera-ntfs-2015-including-license-key-to-r ead-and-write-ntfs-in-mac-os-x-el-capita…

Nailed it. Thank you!

Thank you, Thank you, Thank you!!!!

I have been struggling with this forever!!!!

You are a saint!