problem with mysql pls help

hi i have really big problem in my server
mysql turn off alone
and when i restart the server
there is an file name : /tmp/mysql.sock disappeared
what should i do to solve this problem
at last sry about my english so bad :)

yo mate,

try this /usr/local/etc/rc.d/mysql-server start

if it fails, pls post the errfile located in /var/db/mysql/

i try this many times but sometimes this file disappeared
sometimes not :(

cd /usr/ports/databases/mysql50-server && make deinstall
cd ../mysql50-client && make deinstall
cd /usr/ports/databases/mysql50-server/
make install WITH_XCHARSET=all clean