Our server has been locked by a person who haven't logged out after working on it, so now I cannot access it without restart. Can I somehow allow via SSH fast user switching without restarting the system? It's running Snow Leopard.
To turn on Fast User Switching from the command line:
defaults write /Library/Preferences/.GlobalPreferences MultipleSessionEnabled -bool YES
Change to NO to turn it off.
To trigger Fast User Switching from the command line (if necessary):
#Login Window /System/Library/CoreServices/Menu\ Extras/User.menu/Contents/Resources/CGSession -suspend #Specific User /System/Library/CoreServices/Menu\ Extras/User.menu/Contents/Resources/CGSession -switchToUserID UID_OR_SHORT_USERNAME_HERE
What do you mean with "access"? Access via VNC or Apple Remote Desktop? Do you want to open multiple VNC Sessions?
AFAIK that's not possible.
edit: I found this: http://www.testplant.com/multidesktop.html I hope it helps. It doesn't seem to be very comfortable nor for free.