As stated in bug 1911535, ReaR rpm installation creates an /etc/cron.d/rear file automatically. This cron programming runs a backup at 1:30 in the morning, and it is generally a non desired behaviour.
Why is this ON_QA?
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Important: Red Hat OpenStack Platform 16.1.6 (tripleo-ansible) security update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2021:2119