Plesk fails to load with the following error:
Unable to connect to database: mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'
ERROR: Zend_Db_Adapter_Exception: SQLSTATE[HY000]  No such file or directory (Abstract.php:144)
MySQL fails to start with the error below:
Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'
The server does not have enough free disk space.
Check disk usage:
# df -h
Filesystem Size Used Avail Use% Mounted on
129G 129G 0 100% /var
96G 12G 79G 100% /
/dev/sda1 190M 19M 162M 100% /boot
tmpfs 3.9G 0 3.9G 0% /dev/shm
Free up some space or increase the disk size. Also
du -sh directory_pathcan be used to find the disk usage of directories.