Solución al error : Couldn't start MySQL! while starting XAMPP
sudo chmod 755 /opt/lampp/etc/my.cnf
sudo chmod -R 777 /opt/lampp/var/mysql
sudo chown -hR root /opt/lampp
Reiniciar Xampp.
Starting XAMPP for Linux 1.8.1...
XAMPP: XAMPP-Apache is already running.
XAMPP: XAMPP-MySQL is already running.
XAMPP: XAMPP-ProFTPD is already running.