System: Automatically exclude protected files from rsync

[danisztls]

When doing a system backup rsync will fail when trying to sync files without read permissions and don't know of anyway of making ignore those automatically. The currrent workaround is to add those manually to an ignore file. That's just not practical and instead I want to automatically traverse /etc find those and update rsync ignore file.

Alternatively

Find a less fragile alternative to rsync.