Answer

Mysql logs information about table crash, error etc. in its log file. Depending on your install this log file could be in /var/log/mysql or some other place.

So check out mysql.log and if you see entries like table marked as crashed, then login into the mysqladmin console and repair these tables one by one.

Sample Error from the log.

120119  9:29:14 [ERROR] /usr/sbin/mysqld: Table './developerfeed/accesslog' is marked as crashed and should be repaired
120119  9:29:14 [Warning] Checking table:   './developerfeed/accesslog'
120119  9:29:26 [ERROR] /usr/sbin/mysqld: Table './developerfeed/cache_block' is marked as crashed and should be repaired
120119  9:29:26 [Warning] Checking table:   './developerfeed/cache_block'
120119  9:29:45 [ERROR] /usr/sbin/mysqld: Table './developerfeed/captcha_sessions' is marked as crashed and should be repaired
120119  9:29:45 [Warning] Checking table:   './developerfeed/captcha_sessions'
120119  9:29:46 [ERROR] /usr/sbin/mysqld: Table './developerfeed/sessions' is marked as crashed and should be repaired
120119  9:29:46 [Warning] Checking table:   './developerfeed/sessions'
120119  9:29:47 [ERROR] /usr/sbin/mysqld: Table './justsikh/accesslog' is marked as crashed and should be repaired
120119  9:29:47 [Warning] Checking table:   './justsikh/accesslog'<!>