Accidentally locked out of Mac I removed the staff group and closed my finder window (yes I am a fool for doing this). After closing the window, I effectively lost access to everything on my "Macintosh HD". I re-booted and was happy to see my login screen, but after I login all I have is a grey screen and cursor. 


I rebooted holding Comand+R
I chose "disc utility" and then "unlocked" Macintosh HD
I opened Terminal and typed "password"
I did not reset my password, but clicked "repair permissions and ACL's"
I quit terminal (using Command+Q) and did the same for "reset password utility"
I rebooted and got back to the login screen, but have the same problem


I have a retina Macbook Pro (10.8.2); recovery is 10.8.1. I can access and see my files when I click "open from the recovery mode option", and I know my password, I just need to know how I can reset permissions. Re-formatting is an options, but I don't have any extra hard drives with me, and my main drive is nearly full, so I can't move things around.
You'll probably need to recreate the group staff via the command line.
It should be in /etc/group.

You can check if it exists:

cat /etc/group | grep -i staff


I have staff as the following:

staff:*:20:root


You can create the group again and add root to that group, put it in the sameGroupID etc although I'm not sure if that will do the trick. I never had to do this before so I would recommend before you do anything to connect your Mac via FireWire to another Mac.

Restart your laptop while holding T so it acts like a FireWire drive (no files in use by the system) so you can copy the complete disk...

Easy way to clone would be something like Carbon Copy Cloner.
Other possibility is using the asr command in the Terminal.

The recreation of groups and adding users etc. can be done via the command dscl

There is someone else who had this kind of issue so you could also have a look here:
https://superuser.com/questions/477572/mac-osx-repair-staff-group