iMac 27' Lost All Users Except "Guest User"

[TechieJustin]

We're using an 27" iMac for photography work. Normally there are a few people's logins when you boot up. The user got an error saying the drive was full, forced her to restart and then only Guest User was available at logon.

We tried "resetpassword" command and that wasn't able to complete because it won't list the list of users.

Only guest account show up at login screen - Apple Community

I'm thinking the drive is bad, note below it can't find certain plist files.

 

[MacInWin]

A few questions: What iMac, exactly, is it? What version of the operating system?

Do you have another Mac that you can use to do some diagnostics/repair? If so, you might consider using Target Mode to remove some of the files from the iMac to see if you can get it to boot. It's not good when you overfill a drive to the point where the system does what it did in this instance.

Do you have backups?

Target Mode: Tech Tip: How to Boot and Use a Mac in Target Disk Mode

 

[ferrarr]

Have you tried to startup in Recovery mode?

About macOS Recovery - Apple Support