How to repair mount point when I can't login

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How to repair mount point when I can't login

Here is my problem:

I had two hard drives, "Mac SSD" (primary) and "Mac Data"(secondary). Unfortunately, all of my users home directories were on "Mac Data".

I tried to install an app which complained about the space in the path to my user directory, so I used Finder to rename my drive "MacData" - which Finder was happy to do for me.

Of course (I now realise why), after rebooting, I find that I'm unable to login to any of my user accounts because the paths for those accounts all point to "Mac Data", not "MacData".

So, to fix my problem, I seems that I have to either,

1. Change the path for my user accounts to point to "MacData", or

2. Change the mount point for the drive back to "Mac Data".

I can't work out how to accomplish either of these without being able to log in as a user.

Can I do either of these things via the Recovery function (Cmd-R), or the Single User Mode (Cmd-S)?

Thanks in advance for any help you can offer.

MacBook Pro, OS X Mountain Lion (10.8.4)

Posted on Jul 28, 2013 1:07 AM

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Answer 1

Linc Davis

Level 10

209,541 points

Jul 28, 2013 8:04 AM in response to horsehorse

Boot into Recovery, launch Disk Utility, and rename the volume.

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Answer 2

horsehorse Author

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Jul 28, 2013 9:35 AM in response to Linc Davis

Thanks for your reply.

When I boot into Recovery and run the Disk Utility, I can unmount and mount the volume, but there doesn't seem to be any way to rename it. None of the menu options allow me to rename it, and pressing Enter to rename it doesn't work either. Do I need some additional permissions to rename a Volume in the Recovery Disk Utility, or am I just being dumb?

Thanks again.

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Answer 3

Linc Davis

Level 10

209,541 points

Jul 28, 2013 10:05 AM in response to horsehorse

You should be able to rename it in the Erase tab. Without erasing, obviously.

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Answer 4

iW00

Level 6

8,488 points

Jul 28, 2013 10:34 AM in response to horsehorse

Boot to single-user mode.

First check how is your partition identified, run:

diskutil list

then you can use again diskutil tool to rename partion:

diskutil rename /dev/CORRECT_ID new_name

i.e. diskutil rename /dev/disk1s2 "Mac Data"

Don't forget about "".

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Answer 5

horsehorse Author

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Jul 29, 2013 1:37 PM in response to Linc Davis

Thanks again.

The Erase tab does indeed have an editable dialogue box for the Volume name, but there doesn't appear to be a way to make the change occur once I've edited the name. If I navigate away from the Erase tab, the volume name is reset to its unmodified value. If I choose the "Erase Free Space" operation, to force the software to perform an action (and hopefully change the volume name at the same time), the volume name is reset to its previous value at the end of the procedure.

Is there something I should be doing to make the Disk Utility accept the new volume name?

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Answer 6

horsehorse Author

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Jul 29, 2013 1:41 PM in response to iW00

Thanks for the reply IW00.

If I enter single user mode and type any diskutil command, I get the message:

"Unable to run because unable to use the DiskManagement framework. Common reasons include, but are not limited to, the DiskArbitrartion framework being unavailable due to being booted in single-user mode."

So it seems that I'm unable to use diskutil in single user mode...

Is there another method or utility you can think of to allow me to change a volume name?

Thanks in advance.

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Answer 7

Linc Davis

Level 10

209,541 points

Jul 29, 2013 2:14 PM in response to horsehorse

Select the volume you want to rename in Disk Utility, then click the Info button in the toolbar. In the window that opens, note the Disk Identifier at the top. It will be something like "disk1s2".

Launch the Terminal application by selecting it from the Utilities menu. Very carefully enter this command, but only after modifying it as indicated below:

diskutil rename disk1s2 MacData

Substitute the actual identifier for "disk1s2," if it's different. Relaunch Disk Utility and check that the name has been changed. If it has been, restart as usual.

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Answer 8

horsehorse Author

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Jul 29, 2013 2:26 PM in response to Linc Davis

Thanks for all your help (and iWOO too).

I finally managed to fix my problem by running diskutil from the single user mode, after running the manual commands to start the daemons so that diskutil would work (I found the commands here http://www.system-fabrik.de/diskutil-single-user-mode/).

Once I'd got diskutil to run in single user mode I was able to use diskutil rename to change the name of my drive back to "Mac Data" as you'd both suggested.

I'm very happy I didn't have to reformat my drive because I'd accidentally changed the mount point. Phew.

Thanks again.

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Answer 9

iW00

Level 6

8,488 points

Jul 30, 2013 2:21 PM in response to horsehorse

You can try to boot to Recovery Mode (CMD+R) and run Terminal (from Utilities button on the top panel) and once again use the same terminal command from my post above.

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