What do I do if my MySql.sock file is missing?

1. THIS IS THE MOST IMPORTANT! Back up the /var/lib/mysql directory!!!!!!!
# cp -fr /var/lib/mysql /var/lib/mysql.old

2. Check /var/lib/mysql and /tmp for the .sock file (is it in both places?)

3. Recreate the symbolic link to the .sock file:
# ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock

4. Now check the permissions of the /var/lib/mysql. It should be 0755 and mysql:root. If not:
# chmod 0755 /var/lib/mysql
# chown mysql:root /var/lib/mysql

5. cat /etc/passwd to make sure that the mysql user is there.

6. Does /var/lib/mysql/mysql/host.MYI exist? If not then:
# chmod -R 0660 /var/lib/mysql/mysql
# chown -R mysql:mysql /var/lib/mysql/mysql
# /usr/bin/mysql_install_db

7. Now try to force an update:
# /scripts/mysqlup --force

8. If all else fails, then you may have a corrupted table. No before you do this, TRIPLE CHECK that you have backed up the /var/lib/mysql directory. It fact, check it 4 times!
# rm -fr /var/lib/mysql
# rm -f /usr/sbin/mysqld Then force another update:
# /scripts/mysqlup --force

Now if all if this did not help, then try:

# /usr/sbin/mysqld --basedir=/ --datadir=/var/lib/mysql --user=mysql --pid-file=/var/lib/mysql/Server_HostName.pid --skip-locking &