For the Ram the appliances have 64 min recommendation is 24.
http://support.arubanetworks.com/Documentation/tabid/77/DMXModule/512/Default.aspx?EntryId=14796CP-SW-EVAL (Evaluation Version)
2 Virtual CPUs
80 GB disk space
4 GB RAM
2 Gigabit virtual switched ports.
An evaluation version can be upgraded to a later evaluation version in a manner similar to a
production upgrade.
After upgrading to 6.4, an evaluation version can be morphed to a production VM by using the
morph-vm command. For more information, see the Command Line Interface > System
Commands section in the ClearPass Policy Manager User Guide.
CP-VA-500
2 Virtual CPUs
500 GB disk space
4 GB RAM
2 Gigabit virtual switched ports.
Functional IOP rating for a 40-60 read/write profile for 4k random read/write = 75.
CP-VA-5K
8 Virtual CPUs
500 GB disk space
8 GB RAM
2 Gigabit virtual switched ports.
Functional IOP rating for a 40-60 read/write profile for 4k random read/write = 105.
CP-VA-25K
At least 12 CPUs. (Aruba hardware appliances ship with 24 cores.)
1024 GB disk space
At least 24 GB RAM. (Aruba hardware appliances ship with 64 GB of RAM.)
2 Gigabit virtual switched ports.