There are many alternatives to Duplicati for Linux if you are looking for a replacement. The best Linux alternative is rsync, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Duplicati and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Duplicati are Rclone (Free, Open Source), Spideroak One Backup (Paid), Restic (Free, Open Source) and Déjà Dup (Free, Open Source).
duply is a frontend for the mighty duplicity magic. duplicity is a python based shell application that makes encrypted incremental backups to remote storages. Different backends like ftp, sftp, imap, s3 and others are supported.
Backer is a visual front end to the rsync command. It allows the user to select multiple folders and back them up to multiple locations. It stores your backup settings for you so that all your backups can be run easily using a single button click.