The availability distribution of a group is based on the average availability of all the members present in the specific group for 24 hours.
A group cannot be created in the following cases:
No, a combination of devices and interfaces cannot be grouped together as both of them have entirely different properties. But a device group (group containing devices) and interface group (group containing interfaces) can be placed under one subgroup.
You can add group members automatically to a group during discovery by creating a group with criteria. Please note that in future, during network discovery or when adding a device, if any of the devices or interfaces discovered match the criteria specified in the group criteria, then those devices or interfaces will be automatically added to that group.
Yes. You can configure device downtime schedule for groups by visiting Settings -> Configuration -> Device Downtime Schedules -> Add Schedule and choose filter by 'Groups'.