I've tried use different option chmod 775 /*, chmod 775 /*/*, (why I can't explain to myself), and then i'm rebooting system, amd gdm is not started. I searched the logs for errors and the only thing I found was "GdmLocalDisplayFactory: maximum number of X display failures reached: check x server log for error" - /var/log/messages. if i use xstart, it works and doesn't give any errors. the truth is what xstar is for, I don't understand. I think that some executable file does not work due to the fact that I misused chmod. i've used also mtree -U -f /etc/mtree/BSD.root.dist, var.dist, unclude.dist, sendmail.dist, usr.dist