Hi!
There should be a space between altbackup.php and -profile, i.e.
/usr/bin/php5-cli /home/myusername/public_html
/administrator/components/com_akeeba/altbackup.php -profile=YourProfileID
In order for this to work, you have to go to Components, Akeeba Backup and click on the Component Parameters. Set the "Enable front-end and remote backups" to Yes, then enter a Secret Key in the box below. It's best to use a long secret key consisting of only alphanumeric characters, i.e. 0-9, a-z and A-Z.
Alternatively, you can use the following command line which is more performant, works reliably on Rochen and does not require enabling the front-end backup feature:
/usr/bin/php5-cli /home/myusername/public_html
/administrator/components/com_akeeba/backup.php -profile=YourProfileID
(note that we're using backup.php instead of altbackup.php)
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!