I'm trying to use webmin's Filesystem Backup to do simple backups on a server. I'm trying to create a daily incremental backups however, when I check 'Yes' to 'Just add new files to archive?', it ALWAYS adds ALL files to the archive.

Webmin is using tar with the -u option to update the archive but webmin seems to confuse tar. If I run the exact same command then the archive gets updated but when webmin runs the command it adds all files to the archive. Needless to say, my incremental archive is 7 times the original size after 1 week.

This was happening with webmin 1.420 and I upgraded to 1.520 but I still have the same problem. I have a server running ubuntu and one running Centos and both have the same problem.

Anyone have any idea as to what is happening? Perhaps I should ditch the webmin backup and just use cron and tar.