External USB Hard Drive not showing up, after Yosemite update

I had difficulty with my Mac mounting a 2GB external Seagate USB drive. After much trouble I found the solution was to enable NTFS write support for MAC OSX Yosemite. There is a video on youtube that walks you through the steps: https://www.youtube.com/watch?v=R-2NCRcylK0

Dan, thank you for your post!!

Despite other users posting potential solutions here (seemingly to different issues), I think we have hit upon a winner and I encourage everyone here to give this a try. I was loathe to enable write support if I didn't have to as the data I have on my external is "mission critical" and being able to read it is my primary concern for the time being. I figured if we're able to get read access by enabling write support something is fishy... but it turns out that simply by replacing the NTFS driver (which was one of the steps in enabling write support) you can gain read access without actually enabling write support.

In order read my drive what I did was the following:

1. Unmount and unplug all external drives (at least ones using NTFS)
2. Install OSXFuse http://osxfuse.github.io/ - During the install process be sure to check the box to install the MacFuse compatibility layer
3. Install NTFS-3G http://macntfs-3g.blogspot.com/2010/10/ntfs-3g-for-mac-os-x-2010102.html - From an unidentified developer (usual disclaimers apply)
4. Install fuse_wait https://github.com/bfleischer/fuse_wait/downloads

I did not reboot as one of the software packages recommended. Upon plugging in my drive, it showed up straight away as one would have expected it to from the beginning. I haven't experimented to determine if fuse_wait is actually required, but I am fairly certain that there is a bug in the NTFS driver within Yosemite or it has take some non-standard approach to its implementation. By installing NTFS-3G and OSXFuse we're able to bypass this and use our drives.

Please let me know if this works for you guys.

Cheers!

For those using a Macbook Air, please note the following.

I recently bought an Air and immediately put Yosemite on it. I found that, while all 3 of my external drives still worked normally on my old Macbook, one worked normally when plugged directly into my Air AND normally through a splitter, one worked only through the splitter, and one worked intermittently both ways.

I worked my way up to an Applecare head technician. He had a hunch that it was a problem with power, did some research and confirmed that hunch.

According to him, different ED's require different amounts of power. Older ones generally require more. The Air doesn't supply enough power through its USB ports to power the more power-hungry ones. That's why one of my ED's only works when run through the splitter -- the splitter has its own power source.

That's at least part of the problem some people here are having, I guess, and I hope this piece of information helps.

I have a very slow responding FAT32 thumb drive. You can force Finder to wake up by using the command line. start by entering

diskutil list

This will list the drives, in my case the drive has the address "disk1s1", it's listed at the end of the row that contains your name for the disk ("UNKNOWN" or "NONAME" perhaps). Once you have this type

diskutil mount disk1s1

where disk1s1 is the address from the previous command. This mounts the drive again and Finder finally wakes up. Note that the disk was mounted all along, if you try

cd /Volumes/

before doing all the above you will see your drive there, you can cd into it and list its contents. It's Finder that isn't reacting, not OSX. Not that that makes it any better.

I have the same issue with a thumb drive that worked fine before the upgrade.

If a thumb drive won't work, then it's not a power supply problem. None of my Lacie Rugged drives work. Powered MacBooks off, then started up and still won't recognize the drives. My T/bolt drive works fine, which is always plugged in and I have Time Machine on 1TB and Aperture on the other TB. No issues with Yosemite regarding T/bolt. Only FW800 external drives which I use as backups, etc.

Update. On my iMac, the powered G Drive USB to FW800 I have connected all the time as a back drive for Time Machine. I shut down the iMac, unplugged the cable to the G Drive as well as unplugged the power to the G Drive. Started the iMac, then powered on the the G Drive and connected the cable to the FW800 slot (it's USB to FW800) and Time Machine started to back up. I was unaware that it TM wasn't backing up and had stopped on 11/26/14. Now it's fine.

My 2011 Macbook Pro wasn't recognizing the LaCie Rugged drives. I shut down and powered on my MBP and then plugged in one of the drives to do a vault back up on Aperture. It worked fine. I did 2 back up's on 2 LaCie Rugged drives. No issues after re-starting, etc. I also plugged in a thumb drive and it recognized it.

My wife's 2012 MBP recognizes a thumb drive, but won't recognize the LaCie Rugged I plugged in for a TM back up which I do manually. I re-started and it still won't recognize it. May be a problem with the drive as none of the machines recognize it, it's getting power as I hear it/feel it when plugged in. Tried USB, FW800 same thing. Calling LaCie to send it back and see if they can help with the drive.

Update 2... I read on another post below in More Like This, that leaving the HD plugged in might help. I did and it worked. It finally showed up on the screen and TM started the backup. Hope this helps others.

* I also read that after plugging in the EHD, it shows the EHD in Finder, but not on the screen. Mine did not, so I opened Disk Utility with the EHD plugged in. It showed up in Disk Utility but could not mount it. I ran first aid and it said I would have to re format, etc. I didn't. That's when I read about leaving the EHD plugged in to see if it mounts on it's own. It did.

I had problems with Mavericks and now Yosemite. With Mavericks my disk drive stopped working, and my Western Digital became useless with my Mac. With Yosemite my headphone jack won't work, my Wacom tablet won't work, and my Western Digital external drive, which I finally got to work in some capacity is wiped clean of all my saved data! AND now I can't access it after I restarted my computer. What gives?

I've been a loyal Apple customer, but after these problems and losing massive quantities of important data my loyalty is certainly shaken like a 7.0. Please let there be a fix and someway of recovering my data!

Its definitely an Yosemite and bridge chipset issue and then a drive power thing on top of that.

I just installed 10 2013 iMacs. Upgraded them to Yosemite.

I have one drive from OWC - silver ones with USB2, FW800, FW400 and esata. (its actually a 6TB Raid 0)

I have a 2011 NewerTech Voryager Q dock. I had two bare drives with me. A Hitachi 2TB and Seagate Barracuda TB.

The OWC case inconsistently mounts/ doesn't mount through USB2 to USB 3 on the back of the computer. I have not yet tried it with the Apple Thunder/FW adapter.

The NewerTech Dock mounts one drive no problem and another, well… it mounts but you go to open the drive on the desktop and either nothing happens, or the drive opens up, but there is nothing listed.

All these same drives mount no problem on the same computers before I did the upgrade.

Apple… really? Please fix.

Doug Weiner

PS. I through these machines on my MacBook Pro and a Hackintosh, running ML, 10.8.5 and they all mount just fine.

Doug,

See my previous post if you're still unable to get them to mount in Yosemite. Basically replacing the NTFS driver and using OSXFuse solves the issue (though this shouldn't be something we have to work around, Apple needs to recognize this bug and squash it).

Cheers,
Matt

I just bought a shiny new iPod Shuffle. Same thing with it. Sometimes Finder and iTunes sees it just fine. Other times neither can see it at all. iTunes thinks it's corrupt and suggests that plugging it in again might solve the problem. It never does. When Finder and iTunes decide they can't see it, the only thing that enables them to be able to see the Shuffle is to restart the computer. Really? Apple wants OS X to be like Windows now?

C'mon Apple, this is beyond ridiculous and annoying.

Good advice. However, that my drives are formatted HFS+ is what leads me to believe this is a bridge / 10.10 problem rather than a drive formatting problem.

Wow, thats even worse than I thought. With NTFS not exactly being Apple's priority, I assumed it was a driver issue... looks like that this goes even deeper (and is a bigger bug for Apple). That makes me wonder if NTFS-3G is even required... maybe its more of the HAL/FUSE Layer that is the problem (I don't know the OS X stack, I'm more familiar with Linux), however I might still suggest trying OSXFuse and fuse_wait in your case. That might help trouble shoot the issue and perhaps get your drive(s) working.

BTW, I should also report that this also happened with an external two-drive enclosure formatted as software RAID 0 (via Disk Utility). The enclosure has two eSATA connectors. I connect it to my mid-2012 iMac via a LaCie Thunderbolt-to-dual-eSATA converter box. A couple weeks ago one of the two drives in the external enclosure wasn't recognized or mountable by Finder or Disk Utility. This isn't a power issue because both the dual-drive enclosure and the LaCie converter box have their own power supplies. Again, restarting the iMac was the only way I could find to get the iMac to recognize and mount both of the drives in the dual-drive enclosure.