Wednesday, August 24, 2022

MacOS 12.5.1 update breaks user accounts

The MacOS Monterey 12.5.1 point release, seems to be breaking user accounts on certain Mac configurations. If you have user accounts configured with the user’s Home folder on an external SSD or HD, you should read on BEFORE you attempt to update your Mac to 12.5.1

  • The problem
  • What’s going on
  • How to fix
  • How to avoid

The problem

A number of users have found that after updating to MacOS 12.5.1 their user accounts have been reset and the data in their home folder is unavailable. This includes all user configuration data, user data files and software registrations. This data is not lost but is unavailable to the user. Whether this happens for EVERY user with their Home directory on an external drive, or just for some, is unknown.

What’s going on?

It would appear that, at some point in the update process, MacOS attempts to access the users account without the external drive being mounted. Not being able to find the account data, the update proceeds to create a new home folder for the account on “Macintosh HD,” giving it the same name as the missing External drive. 

Later, when the external drive is mounted the external dive is given a new mount point name because the original name is already in use by the home folder created earlier. For example if the external drive was originally called “Data” it will now be mounted as “Data 1”.

All the user data is still intact on “Data 1” but the Mac is now looking at a “ghost” folder called “Data” which had no user data.

How to fix

If this has already happened to you, all is not lost and you can recover the user data easily.

You will need a second ‘recovery account’ for an admin user with their Home folder on the main “Macintosh HD” drive (the default location). You should already have such an account if you also have users with home folders on an external drive but, if not, it is not too late to create one now.

Log in to this recovery account and in the Finder go to Menu > Go > Go to folder. In the dialogue that pops up, type /Volumes/ and press <Enter>.

What you should see is a list of all the mounted drives, including the drive on which the user data is stored. In this example, it is called “Data 1”. In addition there should be a folder icon called “Data” - this is the ghost folder and it is what is stopping the real drive from being recognised.

  • Unmount “Data 1”
  • Delete the folder “Data”
  • Remount the Data drive (it will now be called “Data” not “Data 1”)
  • Log out of the recovery account
  • Log back into the user account

Everything should now be back to normal.

How to avoid

I haven’t tested this, but will make it part of my future update process.

  • Log into the recovery account (see above)
  • Unmount all external drives
  • Proceed with the update
  • After updating make sure all external drives are remounted
  • Log out of the recovery account and log back in as the normal user

I believe this will avoid any ghost folder issues - something that seems to have plagued MacOS as far back as OSX.

Tuesday, August 2, 2022