URGENT Dépannage serveur linux: mysql démarre plus

Bonjour

J'ai besoin d'un expert en maintenance de serveur Linux, ici Centos6, pour résoudre un problème parvenu sur un serveur dédié chez OVH (leur service de support est ridiculement inutile, depuis 3 jours !)

J'ai donc un serveur dédié chez OVH (centos6 64bits) avec plesk 11. Je l'utilise pour héberger des sites web.

En quelque mot, suite à un disque plein, puis nettoyé, mysql (et apparement "named service") ne redémarre plus :( et donc Plesk non plus.

Voici le résultat d'un /etc/init.d/psa start surle serveur :

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[E-mail visible pour les membres Pro] /]# /etc/init.d/psa start
Starting xinetd service... done
Starting mysqld service... failed
Trying to connect to MySQL... Failed to connect to MySQL: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
Trying to start service mysqld... mysqld is stopped
MySQL Daemon failed to start.
Starting mysqld: [FAILED]

WARNING!
Some problems are found during start(see log file: /tmp/plesk_11.0.9_reset_instance_data.log)

Continue...

Trying to start service mysqld... mysqld is stopped
MySQL Daemon failed to start.
Starting mysqld: [FAILED]

WARNING!
Some problems are found during start(see log file: /tmp/plesk_11.0.9_reset_instance_data.log)

Continue...

Trying to establish test connection... ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysqld/mysqld.sock' (2)
failed

ERROR while trying to establish test connection
Check the error reason(see log file: /tmp/plesk_11.0.9_reset_instance_data.log), fix and try again
Starting named service... failed
Starting postgresql service... not installed
Starting psa-spamassassin service... done
Plesk: Starting Mail Server... already started
Starting psa... done
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Pourtant le fichier /var/lib/mysqld/mysqld.sock existe bien, avec les bons droits apparemment ...

J' ai donc besoin d'un support pour réparer cela et remettre en marche ce satané Plesk ...
J'ai pas un gros budget, au contraire :( merci pour votre aide.