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can't mount external hard drive

Greetings all,

I have a External WD 2TB Hard drive connected on FireWire to the mac.

It used to work perfectly, until today where I decided to reformat it in Encrypted / Journaled partition type.

The Format stopped while doing it with an error message (I don t remember what it said exactly).

But the point is that now when I start my external HD, I see it in the list of hard drives on the left frame of disk utility (all the way at the top),

but if I click on it, I can't mount it.

INFO gives me:

TYPE: Logical Volume Group

Disk Status: Online

Capacity: 2TB

Physical Backing: Disk1s2

In first aid, I can verify / repair, but it still does not work after.

In Partition, I cannot do anything. But it says "This partition contains a locked disk and cannot be resized until it is unlocked"

I tried to reboot, safe reboot.

iMac 24" ; MBP, Mac OS X (10.6.1)

Posted on Sep 3, 2012 2:25 PM

Best reply

Kappy

Level 10

361,741 points

Posted on Sep 3, 2012 2:30 PM

Eject the drive then reconnect it. Do the following once it mounts:

Drive Preparation

1. Open Disk Utility in your Utilities folder.

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.

3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

View in context

24 replies

Dec 26, 2012 1:16 PM in response to Simon Templar 42

open the Terminal.app and try: diskutil cs list

+-- Logical Volume Group 7F6B7190-1693-4A04-B397-2E18FF88C77C

=========================================================

Name: TimeMachine

Size: 499763888128 B (499.8 GB)

Free Space: 499445112832 B (499.4 GB)

+-< Physical Volume 0E07E045-39D0-46F5-8B41-82D0B2FBD942

----------------------------------------------------

Index: 0

Disk: disk3s2

Status: Online

Size: 499763888128 B (499.8 GB)

diskutil cs delete [Logical Volume Group] in this example 0E07E045-39D0-46F5-8B41-82D0B2FBD942

This solved my problem right away!

Sep 28, 2013 3:02 PM in response to Jacob Carter Dando

THANK YOU, JACOB CARTER DANDO! I had an almost identical problem, and your Terminal solution worked perfectly. I was encrypting my entire external drive, rather than just using Time Machine's encryption. Now I'm doing it through TM and have my password structure better documented, hopefully this won't be a problem in the future.

Sep 29, 2013 11:54 AM in response to Cloudster

Happy to have contributed! 😉

Dec 25, 2013 10:45 AM in response to Jacob Carter Dando

Once again....much thanks Jacob Carter......worked w/o having to use another OS!! Cheers.

ocksway

Level 1

0 points

Dec 26, 2013 12:14 AM in response to Simon Templar 42

Found this on another thread...worked great for me! (Thanks to BDAqua)

Open Terminal and type these commands carefully with the spaces & change 320GB HD to the name of your drive.

sudo chflags 0 "/volumes/320GB HD"

sudo chown root "/volumes/320GB HD"

sudo chmod 1775 "/volumes/320GB HD"

sudo -k

Sunny259

Level 1

0 points

Jan 1, 2014 6:39 PM in response to Simon Templar 42

Just right click on the drive in disk utility and click unlock. I think your drive is encrypted and I am not sure for some reason mac is not prompting for password.

Sep 5, 2015 4:20 AM in response to ocksway

Worked like a charm. Thanks Sunny259.

Nov 20, 2016 10:55 PM in response to Sunny259

I have the same problem. Where is 'unlock' ? I cannot find in the disk utility ?

Eric Root

Level 10

684,045 points

Nov 21, 2016 5:40 PM in response to Cute Production

Look under the File menu.

You might want to consider starting a new discussion. Since this one is a couple of years old, less people are likely to look at it. A new post would be much more visible. You can link to this one.

can't mount external hard drive