Recently upgraded to OpenEMR 3.2.0 from version 3.1.0 on Ubuntu Hardy Heron. Initially was able to backup on a daily basis but for the past two to three days end up in an error message: maximum exec time 30 s exceeded /usr/share/php/Archive/Tar.php on line 1046.
OpenEMR 3.2.0 is bigger, so takes longer to back up. Can increase php execution limit time by modifying your php configuration file (php.ini) setting:
max_execution_time = 60
(if you modify the php.ini file, ensure you restart the apache server)