set backup job in scheduler
in conf.xml
in section
insert
<job type="system" name="check1"
class="org.exist.storage.ConsistencyCheckTask"
cron-trigger="0 0 23 * * ?">
<parameter name="output" value="export"/>
<parameter name="backup" value="yes"/>
<parameter name="incremental" value="no"/>
<parameter name="incremental-check" value="no"/>
<parameter name="zip" value="yes"/>
<parameter name="max" value="2"/>
</job>
if not present