We are running MySQL Server 5.1 in CentOS (Linux based) environment in cloud computing. Since our database getting grow in rapid manner, I wish to find out the maximum database size.

If the size below TB means, We need to migrate the database along with system configuration. (For all kind of databases like MSSQL, MySQL, Oracle etc.,)

Please update this along with size and system configuration.

MySQL can handle terrabytes of data I wouldn't worry about the size if you can afford the disks

unlimited, if you can afford the hdd. I recommend use innodb for your data structure