From time to time mySQL databases can get corrupt, whether it due to lack of disk space, power failure, or just an error.
Repairing MyISAM mySQL Tables/Databases:
cd /var/lib/mysql/DBNAME
#^ Please note that we assume your mySQL data directory is /var/lib/mysql
myisamchk *.MYI
Repairing ISAM mySQL Tables/Databases:
cd /var/lib/mysql/DBNAME
#^ Please note that we assume your mySQL data directory is /var/lib/mysql
isamchk *.MYI