[deanhills]

Thanks for suggesting this extension, looks like It's good for Dropbox backup.
What do you suggest if I'd like to back up to  a selfmade OwnCloud server? Does it support?

As long as you have an installation of WordPress I'm sure it should work with any server.  I don't have very big WordPress sites so don't know how it would work with larger sites.  But I'm very happy with this plugin.  Previous to this plugin I used Duplicator plugin that is also good, but not simple to use.  I found duplicator didn't work with all servers and was picky with the specs of the server, whereas with the Allinone plugin I haven't had a single issue yet and I've used it with a variety of VPSs.

For larger sites Updraftplus plugin comes highly recommended.  Particularly for those who like to work with Cloud and Dropbox.  I haven't used it myself, but it does come with very good reviews and has been around for a long time.  You can check it out for yourself:
https://wordpress.org/plugins/updraftplus/