When taking an online vm snapshot it is highly recommended to have qemu guest agent freezing the guest before taking the snapshot.

With that said, we are allowing to take an online snapshot if guest agent doesn't exist. We want to make the user as aware as possible that this is not recommended, and explain how it can be fixed (installing qemu GA). To do that we want to add an alert that will be fired in case on online snapshot occurred without a GA, the alert will refer to a run-book explaining how this should be fixed.  

Even if GA exists it is possible to have freeze error. When that occurs the snapshot can succeed or fail eventually. In either case we want to present that there was some failure during freeze and we can't fully guaranty that the snapshot is optimal. An indication will be presented on the snapshot indications. Once this indication is set we want to fire and alert explaining the situation and referring to a run-book explaining what can be done.