Want to highlight a helpful answer? Upvote!

Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

User profile for user: fnu lnu
fnu lnu Author
User level: Level 1
0 points

MacBook Pro won't recognize external hard drive; error during unencryption?

I have a Seagate external HD with its own power source. I had previously formatted it extended journaled and turned on whole-disk encryption, but hadn't been using it. I wanted to add it as a second TimeMachine drive to my AirPort Extreme. I added a USB hub to the Extreme and plugged in the second drive, but it never showed up in Finder. (The first drive, also now plugged into the hub, was recognized and continues to work fine.)

So I plugged the second drive directly into my MacBook Pro. It showed up, I entered the encryption password, and then turned off the encryption. Finder showed no files on the drive, which I didn't think was correct, but couldn't remember for sure.

I ejected the drive and plugged it back into the hub plugged into the Extreme. It still didn't show up. So I again plugged it back into the MacBook Pro, and now it won't show up there either. When I plug the USB cable into the MacBook Pro, I can hear the drive spin up and the normal initial chatter, and its LED is on. So I believe the cable is good, and the drive is not broken in any gross way. I've shut down and restarted the MacBook Pro, which didn't solve the problem.


Any ideas? Is it possible that when I turned off the encryption, I should have waited longer before ejecting it, and somehow screwed it up? There was no progress window, message, or spinning cursor, and it ejected fine.


MacBook 15" Retina (2012), Mavericks. Thanks in advance.

MacBook Pro (Retina, Mid 2012), OS X Mavericks (10.9)

Posted on Nov 21, 2013 7:25 PM

Reply
Question marked as Best reply
User profile for user: Linc Davis
Linc Davis
User level: Level 10
209,535 points

Posted on Nov 22, 2013 2:30 PM

Does it show in Disk Utility?

View in context
10 replies
User profile for user: fnu lnu
fnu lnu Author
User level: Level 1
0 points

Nov 22, 2013 7:32 PM in response to Linc Davis

Yes! It says the format is "Locked Logical Partion," unmounted. (The disk just has one partition, and the capacity shown is the full capacity of the disk.) When I click the "mount" button, it just blinks, and the new log entry says it is still a locked logical partition, unmounted.

Since at most the drive contained back-up copies of files I have safely backed up elsewhere, I decided I would just reformat it with a single pass erase. When I tried, I got the error, "Disk object invalid or unable to serialize." However, at the same time, I noticed a progress bar on the main Disk Utility window saying it was erasing, though the disk name it used (disk2s2, I think) was not one I had seen before. When I hit "ok" on the error window, the drive now appeared as mounted and showed up in Finder. DU says it has several folders and files, but they do not show up in Finder.

I ejected and plugged it back in, with no different results. So I reformatted again, this time with no erase, and it seemed to succeed, and the reported number of folders and files went down, but not to zero, and the used space only changed slightly. When I clicked on the drive itself, then back on the sole partition, the DU display went back to the original number of folders and files. Weird.

I was then able to plug it into my Extreme and everything seems to be working normally. Thank you for your help.

Reply
User profile for user: Linc Davis
Linc Davis
User level: Level 10
209,535 points

Nov 22, 2013 8:29 PM in response to fnu lnu

Triple-click anywhere in the line below on this page to select it:

{ diskutil list; echo; diskutil cs list; } | open -ef


Copy the selected text to the Clipboard by pressing the key combination command-C.


Launch the Terminal application in any of the following ways:


☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)


☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.


☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.


Paste into the Terminal window by pressing the key combination command-V. I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting.


Wait for a new line ending in a dollar sign (“$”) to appear.


A TextEdit window will open with the output of the command. If the command produced no output, the window will be empty. Post the contents of the TextEdit window (not the Terminal window), if any — the text, please, not a screenshot. The title of the window doesn't matter, and you don't need to post that.


If any personal information appears in the output, anonymize before posting, but don’t remove the context.

Reply
User profile for user: fnu lnu
fnu lnu Author
User level: Level 1
0 points

Nov 23, 2013 7:48 PM in response to Linc Davis

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage 250.1 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Macintosh HD *249.8 GB disk1

/dev/disk2

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk2

1: EFI EFI 209.7 MB disk2s1

2: Apple_HFS Seagate 1TB 999.9 GB disk2s2



CoreStorage logical volume groups (1 found)

|

+-- Logical Volume Group 45906159-A46E-437A-A62D-2D0C45CE2506

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

Name: Macintosh HD

Status: Online

Size: 250140434432 B (250.1 GB)

Free Space: 16777216 B (16.8 MB)

|

+-< Physical Volume BC3261D8-2C8E-4390-BA41-380EFC3183ED

| ----------------------------------------------------

| Index: 0

| Disk: disk0s2

| Status: Online

| Size: 250140434432 B (250.1 GB)

|

+-> Logical Volume Family 6AC83553-C298-4E59-8329-1025BDA86CFD

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

Encryption Status: Unlocked

Encryption Type: AES-XTS

Conversion Status: Complete

Conversion Direction: -none-

Has Encrypted Extents: Yes

Fully Secure: Yes

Passphrase Required: Yes

|

+-> Logical Volume 8409A610-2851-4540-8A18-EE1179ED8D9A

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

Disk: disk1

Status: Online

Size (Total): 249804886016 B (249.8 GB)

Conversion Progress: -none-

Revertible: Yes (unlock and decryption required)

LV Name: Macintosh HD

Volume Name: Macintosh HD

Content Hint: Apple_HFS

Reply
User profile for user: Bernhard Grabowski
Bernhard Grabowski
User level: Level 1
0 points

Apr 17, 2014 12:52 AM in response to Linc Davis

I've got a similar problem, but I do not want to erase.

I accidentally ejected my Time Machine external HDD while decrypting it.

Now the HDD does not mount...


How to proceed? Plug it back into the MAC where it happened and hope the process will pick up where it left?


/dev/disk4

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk4

1: EFI EFI 209.7 MB disk4s1

2: Apple_CoreStorage 999.9 GB disk4s2

3: Apple_Boot Boot OS X 134.2 MB disk4s3


+-- Logical Volume Group 04241FBA-F3D1-4DC0-BFFA-57C029643C7E

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

Name: TMBackup

Status: Online

Size: 999858069504 B (999.9 GB)

Free Space: 0 B (0 B)

|

+-< Physical Volume D3E51D60-F4FB-42C6-8F4F-6134CAAF80CB

| ----------------------------------------------------

| Index: 0

| Disk: disk4s2

| Status: Online

| Size: 999858069504 B (999.9 GB)

|

+-> Logical Volume Family 2DC501F5-F4C0-4733-A9B7-8697F900466D

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

Encryption Status: Locked

Encryption Type: None

Conversion Status: Converting

Conversion Direction: backward

Has Encrypted Extents: Yes

Fully Secure: No

Passphrase Required: No

|

+-> Logical Volume 38AD36FF-F520-4678-8FFC-12B33C2242A9

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

Disk: -none-

Status: Locked

Size (Total): 999539298304 B (999.5 GB)

Conversion Progress: -none-

Revertible: Yes (unlock and decryption required)

LV Name: TMBackup

Content Hint: Apple_HFS

Reply

MacBook Pro won't recognize external hard drive; error during unencryption?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.
Learn more Sign up