When you install the c-mode simulator, do you only get 1 node and is that the limit. If not, how do you add more nodes to the cluster? Do you install additional simulator and join them to the existing cluster?
Correct. Each VSIM is a standalone node. You bring up 2 separate VSIMs. The first one you create the cluster and on the second join the existing cluster. The cluster create wizard (and vserver create wizard once you are up) is really nice and you don't have to setup the interfaces anymore and it will auto assign IPs to the cluster network on e0a and e0b. You can still manually configure these though. Once you have both nodes up you can run "cluster show" and see both nodes in the cluster.
The cluster create will ask for a cluster-wide IP (default on e0c) then a node management IP for that node (also default on e0c) then the other node you join will ask for node management (e0c) so you will have 3 IPs (one cluster IP and node management per node). Then you will be ready to create aggregates, volumes, Vservers and LIFs.