External Hard Drive not Mounting

can you please help me unlock my iCloud to

I had the same problem with a Western Digital 2TB My Book Studio.

It showed up in disk utility but not in finder.

What I did was right click in the external HD that appears in disk utility and from there you can click show in fnder!

It seems like the partition had a hidden attribute. I was in a hurry so I just grab the HD in finder and add it to my favorites bar in the left side of finder.

I think that I need to research about the hidden attribute but for now I can work and access to my HD.

I hope this works for anyone having the same problem.

Edit:

I also found how to unhide the partition. Just use the chflags mettod.

Open terminal and type:

"chflags nohidden "

With a space at the end and drag and drop the drive from finder to terminal and hit enter.

Use what I explain earlier to get access to your HD in finder using disk utility shorcut

Thank you

roadparc

I had the same problem too, but with a USB 3.0 External Western Digital 3TB HD, My Passport For MAC.

While running a Late 2009 Mac Desktop, with Yosemite 10.10.5, I was attemping to back up with Apple's Time Machine application my Desktop Computer onto my USB 3.0 External Western Digital 3 TB Hard Drive, My Passport For MAC.

The 3 TB HD icon wouldn't show up on either the Finder window or Computer screen, on my Desktop computer, but would show up within the Desktop computer application, Disk Utility, on the left side of it's window. There it would allow me to select Verify and Repair, but once the process ran its course, a window would pop up to say an error has occured: "Couldn't open disk" or "The disk couldn't be unmounted". Now, I know the 3 TB HD was running because I could feel it the rotation of the hard drive and I could see that it's exterior white light was on. So here's how I was able to bring back! Since I had access to an additional computer, with the latest Operating System, Sierra 10.12.3., I plugged the USB 3.0 External Western Digital 3 TB Hard Drive, My Passport For MAC. into a laptop. As some time had passed, 15 to 20 minutes, while I was discussing this issue over the phone with Apple Care, yet before we were able to implement any Apple Care solutions, I opened up the Finder window and sure enough there and on the computer screen, was the 3TB My Passport For Mac! Recap: From my experience, find a newer second computer, even a friend's, who's running the latest operating system. (Allow some time) for the USB 3.0 External Western Digital 3TB HD, My Passport For MAC to be recognized by the computer, a laptop in my case. Check back later with it's Finder window or Computer screen and with some luck, it appears! You're back in business. If not, although I never got around to it, I'm sure Apple Care will have some suggestons. Good Luck and Keep me posted!

Well had the same problem. But found solution!
One of my USB-SATA interfaces does not work. This is correct no way to mount.

But a WD external disk mounted immediately. One other USB-SATA interface I have also mounted immediately.
It seems Sierra does not have all drivers for all USB-SATA devices installed.

Thank you very much nexkulit! Though I had Paragon NTFS on my system already, I downloaded and installed Seagate's version and voila - my drive showed up. A check on volume said it was "dirty" (whatever that means), so I quickly copied the contents back to my iMac HDD and am in the process of doing a secure erase on the stupid thing, right before I throw it in the garbage. I will NEVER buy a Seagate peripheral ever again. This thing has been a nightmare.

Even during the copying it managed to mess things up and reboot my system. Took forever to get the thing mounted again. I hate Seagate with a passion now.

Same here, WD hard drive. Almost shipped it for warrenty repair becaseu I assumed the drive was faulty. Then plugged into a Windows PC and it mounted.

No issues appears again. No work arounds, reboot of the OS donesn't help.

**** !

I have a solution.

1. Open terminal
2. Run some commands to find the "id" of your drive
3. Ask the system manually to mount your drive.

Step 1

Open Applications > Terminal (the black/white empty screen where you can write text into it)

Step 2

Run the following command:

diskutil list |awk '/external, physical/,/^$/' | awk ' /[1-9]+[0-9]*:/ { print $3, $6 } '

In my case this outputs:

EFI disk2s1
m disk2s2
Recovery MB

And the drive which I'm interested in is "m", so my "ID" is disk2s2

Step 3

Run the following command

diskutil mount disk2s2

Your drive should now be mounted.

Theory

For the technical explanation of what is going on: The kernel is able to load the usb device, but (I assume) that the system event messaging subsytem fails to handle the new usb storage device detected event for whatever reason (process restart, wrong key name.. what ever.. it's random in nature). therefor kernel sees the device but user space is not, because device is not mounted. The above fixes the loss of the system event notification by doing it manually.

I'm having the same issue. The delay is that the connected disk is running fsck in the background before it shows up, which can take some time. If you open a terminal window, cd to /var/log and "tail -f fsck_hfs.log" (or another if not hfs) you'll see this running.

That said, my fsck never completes successfully, which is an issue that disk disk mounts read-only.

Perfect. Thought I was lost...Elegant solution.

Worked for me! Added a USB extender and *BAM* my Seagate 4TB hard drive showed up.

I'm experiencing a similar problem. I have a G Drive Mini 1T 0G02577 which is failing to mount. This is connected to a MacBook Pro (Retina, 15-inch, Late 2013) which I have recently updated to Sierra 10.12.4. It may be coincidence but I have only had this problem since updated the OS, until then the disk was mounting and running without any problems.

I can see the drive in Disk Utilities and also in ‘About this Mac > System Preferences > Hardware > USB', but it will not mount. I have seen that some other users have experienced similar issues with portable drives failing to mount since this OS update so I am wondering if this may be the problem?

I desperately need to retrieve the data on the disk. If anyone has any advice I would be so grateful of any help resolving this.

This was usefull for me many times! http://www.tuxera.com/products/tuxera-ntfs-for-mac/

I did your suggestion while sipping on vodka: plugged the external drive to a Windows laptop... replugged it to my Macbook Air.. and voila, external drive is showing on the desktop.

It may have been the vodka, though. But seriously, thanks for this suggestion. No downgrading to El Capitan needed!

It has happend to me as well, what i did , i had older mac with old system and i just run older disk utility repear disk permission and did fix the problem.

New systems can not do the same job......

Lacie drive do have some issues if you format HD as Ex fat.....

This did not work for me.
I spent some time searching and came up with this solution that did work:

Opwn the finder preferences:
Finder > Preference
In the general tab reset the default values:
1. Show these items on the desktop (uncheck all)
2. New Finder Windows show (All My Files)

3. Open folders in tabs instead of new windows (check)

Then I unplug and plug back in my HD.

I then Reset System Management Controller SMC:

Shut down

Press and hold

shift, ctrl cmd(option) + power

When I booted and set my finder preference back to show all external HD's. everything worked and I have not had a problem since.

Now even my Tech Tool emergency disk is performing correctly.

iMac Late 2013 27"

Sierra 10.12.4

Hi,

i ran the commands you instructed to run in terminal. I have a 15 inch pro retina from 2014 and I have a seagate 2TB drive. after running the commands it says - unable to find disk for seagate. I'm starting to wonder if my usb cord is broken or the external drive itself. any ideas?

Follow these instructions: https://discussions.apple.com/thread/7904838?start=0&tstart=0

After this, my problems with external usb/thunderbolt drives were solved.

why my verbatim plug in macbook pro touch bar is working but cannot read my flash drive but before it can read my flash drive? The flash drive is not showing in finder and disk utility but when i charging via the verbatin it is work

Aatt 123456aatt

Yeah this discussion is useful

https://discussions.apple.com/thread/7904838?start=0&tstart=0

1. Relaunch the Finder.

The discs may be mounted and available; however, if the Finder is having troubles displaying them then it may appear as though the discs are not mounted. Press the Option key and right-click the Finder icon in the Dock, and choose "Relaunch".

2. Change the port.

Sometimes there are differences in the USB ports on the system, which result in power or speed differences that can result in external devices not being recognized properly. Try each USB or FireWire port available on your system (use FireWire 400/800 adaptors or conversion cables if necessary) to see if that helps. You can also try this when booted into Safe Mode, to see if any third-party plug-ins or nonessential features of OS X are contributing to the problem.

3. Plug in power adaptor (if available).

Some external drives come with optional power adaptors (especially smaller and more portable drives). If you have one, try plugging it in so the drive is not reliant upon bus power. Low power can definitely prevent a drive from working properly.

4. Avoid daisy-chaining.

When troubleshooting USB or firewire devices, unplug all except for the problematic device (and your keyboard and mouse, of course) and plug it directly into your system. Do not route it through the keyboard or a USB/FireWire hub, as this is yet another source for incompatibilities and problems.

5. Try a different connection type.

Some devices have both USB and FireWire ports, so use each of them to see if the device works. If it does with any of the ports, then you know the device is probably not to blame and can focus on troubleshooting the bus/connector that is causing issues.

6. Run general maintenance.

Give your computer a once-over maintenance run. Reset the PRAM and SMC, followed by booting into Safe Mode and clearing caches and performing a permissions fix with various maintenance utilities (Cocktail, Yasu, OnyX, just to name a few). Then boot normally and reboot again (the first boot will fill caches and be a little slower than the second) before trying the problematic external drive.

7. Drive problems

Last but not least, there may be problems with the drive itself, which can be caused by a number of issues including power or connection interruptions without properly unmounting the drive (a frequent occurrence for external drives). For information on how to tackle partition and volume problems,see this article.

Hope this will be helpful.

How you downgrade?

If you want to write to or edit an NTFS-formatted drive on macOS, there are several ways to do it. You'll be able to read what's on the drive, but have full compatibility to access and edit what's on it. there is a way to easily add that using Paragon NTFS for Mac.

for more details please click the link

[https://singapore.zapplerepair.com/detail-list-macbookpro.php?id=103&slug=how-to-write-and-edit-drive-ntfs-in-mac-os]

Any luck with this? I’m in a terrible fix …

First, check if you have a NTFS hard drive. You can do this by going to Disk Utility (by pressing Cmd + Space)

If you have a NTFS file system, you can try the Paragon NTFS Driver (https://www.seagate.com/support/software/paragon). However, I haven't had much luck with the NTFS file system on Mac. So I've ended up formatting them to ExFAT.

If you have an ExFAT hard drive that isn't mounting, try running the following commands -

1. Plug in your hard drive
2. Run ps aux | grep fsck - This will show if fsck is using your hard drive (typically happens when you don't eject it properly)
3. Run sudo pkill -f fsck - This will kill the process and immediately show your hard drive in Finder

Hope this works

i have the same issue bought a retina, my external hard drive was working fine in my old mac it was locked with password. my pass is correct when i tried it on Data Recovery software. but now in both of my Macbook pro the external hard drive is detected but not working and not even asking for password like Data Recovery software. if someone find a solution please help.