Hello - as Ruijuan points out the message you're getting is from the self-signed certificates leveraged by SystemManager and OCUM. That said, you can install a certificate issued by a trusted CA on both your cluster (thereby addressing the SystemManager warning) as well as install a certificate onto the OCUM server. For our purposes, we chose not to pursue that approach but instead put our infrastructure behind a web load-balancer with internally trusted certificate installed. HTTPS warnings about self-signed certs get stripped before the client sees them and we also consolidate our storage management behind our data center firewall.
If you'd like to pursue the cert installation let me know as I took some notes when we first started down that path (i.e. installing trusted CA certs everywhere).
That said, the warning is mostly just an annoyance - it doesn't indicate anything other than your browser trying to protect you from a potentially unsecure web site. Since there's no chance someone is trying to spoof your SystemManager/OCUM web sites internally by leveraging a self-signed certificate, it's not really a big deal (unless your internal security scanning tools are lighting you up for it).