hi i have a fedora core 7 server with mysql and when i try to restart my server it get this error:

Can't start server: can't create PID file: No space left on device

and on my website i get this error also

Warning: mysql_connect() [function.mysql-connect]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) in /var/web/public_html/vsadmin/db_conn_open.php on line 22
You need to set your database connection in vsadmin/db_conn_open.php.

what can i do?