The Interface and Disk Cache (that is available next to your device names under the Groups menu) are quick tools for setting up interfaces and disk graphs on your devices.
These caches provide useful mechanisms for indexing disks and interfaces. For example, commonly you want to graph your interfaces by their ifName (interface name) which is commonly something like 'Se2/1'. Doing a lookup each time you gather data would be very time-consuming, so the cache allows you monitor an interface by using it's name, and NetMRG will do the mapping to the correct ifIndex. NetMRG will do the same thing for disks
The options from next to your device are as follows
View Interface Cache: This is only available after you have cached your interfaces. Most of the management is done through here
Recache Interfaces: If you add or remove interfaces to your device, this can force a recache. You can also setup NetMRG to automatically recache your interfaces when the device reboots or the number of interfaces changes by editing your device.
View Disk Cache: Like the interface cache; the list of disks that NetMRG currently knows about.
Recache Disks: You'll probably only do this once when you create your device (unless you add/remove disks a lot).
Inside the Interface Cache
Checkboxes: You can select multiple interfaces to monitor by using the '*' (all), '0' (none), and '-' (inverse) items, or by clicking each checkbox individually.
View: View the graph that has been created by clicking 'monitor/graph'.
Monitors: View the monitors under the subdevice that was created by clicking 'monitor/graph'.
Monitor/Graph: Apply the graph template selected in the dropdown box by clicking this item
Dropdown box: The list of graph templates that are available in your NetMRG installation; it's very useful when you have different types of interfaces with different monitors you want applied to an interface (maybe you have one graph with a maximum line, or different multiplers to show bits instead of bytes).
Inside the Disk Cache
The options inside the Disk Cache are very similar to the Interface Cache. Refer there for their descriptions.