backup of mysql

There is no Networker Module for MySQL if this is what you're looking for. I recommend to create database dumps into a client's directory and perform a regular backup of the dump files.

Linux in any case would allow backing up files in use at the time of backup so backing up simply as file system backup should not be a problem.

I'd strongly discourage from backing up database files while they're in use. Even MySQL recommends to use LOCK TABLES and FLUSH commands to clear internal caches before backup. Please see http://dev.mysql.com/doc/refman/5.0/en/backup.html for more information.

Agreed with dk - use either mysqldump or mysqlhotcopy.