Now the backup runs still without any error message and a proper log:
This sounds like two unrelated configuration errors which do not affect the execution of the backup at all:
1. You are redirecting the standard output to /dev/null in this CRON command line. This means that the script's output is not visible and is not logged anywhere. Try removing the > /dev/null part from your CRON command line.
2. If you get no Akeeba Backup log file you have set the Log Level to None in the Configuration page of Akeeba Backup. Please go back there and set the log level to "All Information And Debug". Then retry backing up. Go to Manage Backups. There should be a View Log button next to the backup attempt which will let you view and download the log file. Even if you cannot view the log file click the download button all the same. You will get a .txt file with the log.
but the file on Amazon S3 has only 10.00 Mb (before it was 25.8 MB and there was no change within this website). And it is not the only one with the same resultat. And all of those backups are startet manually without any other action during the backup
I believe this has to do with a bug regarding part sizes that are an integer multiple of 5. Please try using the latest dev release from https://www.akeebabackup.com/download/developer-releases/akeebapro/rev494aaa8.html I thank you in advance for your feedback!
Nicholas K. Dionysopoulos
Lead Developer and Director
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