Support

Actually, Akeeba Backup works fine. The problem is that your CRON server kills the backup before it's complete. This happens because your host has applied a time limit. This is something we've explained for the last 14 years and we know how and why it happens even if very few hosts (basically white label resellers) do not, in fact, understand how the Operating System on their servers is configured.

The most widely used way for this kind of time limits IS NOT the PHP execution time limit. That's a common misconception; the PHP execution time limit has no effect on PHP CLI, as documented by PHP itself. The root cause is, in fact, the CPU usage time limit applied by pam_limits.so, a component of the GNU/Linux family of operating systems. These limits are set up in the /etc/security/limits.conf file or one of the files in the /etc/security/limits.d directory and can be partially overridden in the user's .profile file.

Your host needs to make a change in any of those places to increase the CPU time limit for your user, at least for when it's using CRON jobs. The time limit should be at least as much as it takes to run a backup to completion from the backend of your site. You can determine that by running a backup from the backend of your site and take a look at the reported Duration. That's the number you are looking for.

Contact your host and link them to this support ticket. They will know what to do. The only thing you need to tell them is how long your backups run.

If you're curious and don't mind the gory, technical details I suggest you read this article on user limits (ulimit) in Linux.