Automated backups too long - backup half of them (even or odd)?

Hi,

I currently use Moodle 3.7.5 on a server with CentOS 7, avec PHP 7.1.33 et MariaDB 5.5.64.

My automated backup process includes logs, and takes a long time since some months. I have problems, and task don't finish correctly. I sometimes have problems with "!!! La table « backup_logs » n'existe pas !!!".

I wonder if i could make a modification to backup courses depending on there even or odd ID, respective for even or odd day.

I think i should modify the file backup/util/helper/backup_cron_helper.class.php to add some lines in the run_automated_backup function, just before the line containing "// Check if the course is not scheduled to run right now", but i'm not sure what to add exactly.

If someone could help, i'd be happy.

Séverin