I had a two simple KVM host with Webmin/Cloudmin installed on them. Authentication was by PAM module (to allow auth by LDAP/AD user). I changed one KVM host (HOST1) to a master and added second KVM host (HOST2) as a physical system to HOST1.
Exactly after this change/add I can't login to Webmin/Cloudmin in HOST2 by any user (local in shadow or in AD). I tried to disable PAM auth in miniserv.conf, I tried to do it by opening Webmin thought HOST1 (it's bypass auth), but nothing helps. Still I can not login to Webmin/Cloudmin in HOST2 directly. So when HOST1 will be down I wouldn't login to the HOST2 system.