In case of broken databases (InnoDB engine) try:
Either delete the whole db and restart rm /var/lib/mysql/ibdata1
#OR
mysql --innodb_force_recovery=1 /*+1 if it fails ... wird in 5.5.44 nicht erkannt #http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html#
mysqlcheck --all-databases
mysqldump --force --compress --triggers --routines --create-options -uroot -p --all-databases > /home/pi/alldb-recovery.sql
mysqladmin -uUSERNAME -pPASSWORD shutdown
rm -fdr /var/lib/mysql
mkdir /var/lib/mysql \ chown -R mysql:mysql /var/lib/mysql \ /usr/local/bin/mysql_install_db \ chown -R mysql:mysql /var/lib/mysql
mysql -uroot --compress < /home/pi/alldb-recovery.sql
/usr/local/bin/mysqladmin -uroot flush-privileges
#OR
``sudo /etc/init.d/mysql status`
``sudo /etc/init.d/mysql stop`
sudo cp -r /var/lib/mysql /home/pi/sicherung/mysql
sudo rm -r /var/lib/mysql/klima_growbox
sudo rm /var/lib/mysql/ibdata
sudo rm /var/lib/mysql/ib_logfile0
sudo rm /var/lib/mysql/ib_logfile1
``sudo /etc/init.d/mysql start`
http://www.tecmint.com/mysqladmin-commands-for-database-administration-in-linux/