Big problem with mysql on my server

[Spheerys]

My server is now inaccessible.
Here the logs files :

/var/log/daemon.log :

Code:

Nov 15 18:08:23 lumiere mysqld_safe: Number of processes running now: 0
Nov 15 18:08:23 lumiere mysqld_safe: mysqld restarted
Nov 15 18:08:24 lumiere mysqld: 091115 18:08:24 [Note] Plugin 'FEDERATED' is disabled.
Nov 15 18:08:24 lumiere mysqld: 091115 18:08:24  InnoDB: Started; log sequence number 0 43665
Nov 15 18:08:24 lumiere mysqld: 091115 18:08:24 [Note] Event Scheduler: Loaded 0 events
Nov 15 18:08:24 lumiere mysqld: 091115 18:08:24 [Note] /usr/sbin/mysqld: ready for connections.
Nov 15 18:08:24 lumiere mysqld: Version: '5.1.40-0.dotdeb.0-log'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  (Debian)
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [ERROR] /usr/sbin/mysqld: Table './forum/ibf_cache_store' is marked as crashed and should be repaired
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [Warning] Checking table:   './forum/ibf_cache_store'
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [ERROR] /usr/sbin/mysqld: Table './forum/ibf_sessions' is marked as crashed and should be repaired
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [Warning] Checking table:   './forum/ibf_sessions'
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [ERROR] /usr/sbin/mysqld: Table './forum/ibf_topics' is marked as crashed and should be repaired
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [Warning] Checking table:   './forum/ibf_topics'
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [ERROR] /usr/sbin/mysqld: Table './forum/ibf_forums' is marked as crashed and should be repaired
Nov 15 18:08:29 lumiere mysqld: 091115 18:08:29 [Warning] Checking table:   './forum/ibf_forums'
Nov 15 18:08:32 lumiere mysqld: 091115 18:08:31 [ERROR] /usr/sbin/mysqld: Table './forum/ibf_posts' is marked as crashed and should be repaired
Nov 15 18:08:32 lumiere mysqld: 091115 18:08:31 [Warning] Checking table:   './forum/ibf_posts'

I had repaired theses tables yesterday

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Is there specials parameters to fix when there is one big database on the server ?