1. Document your systems when you build them or do the legwork after...
2. As good an answer as I have found - after a single google it was the first hit:
PowerVM QuickStart
PowerVM Types
• PowerVM inherits nearly all the APV (Advanced Power Virtualization) concepts from Power 5 based systems. It uses the same VIOS software and options as the previous APV.
• PowerVM is Power 6 specific only in that it enables features available exclusively on Power 6 based systems (ie: Multiple shared processor pools and partition mobility are not available on Power 5 systems.)
• PowerVM (and its APV predecessor) are optional licenses / activation codes that are ordered for a server. Each is licensed by CPU.
• PowerVM, unlike its APV predecessor, comes in several different versions. Each is tiered for price and features. Each of these versions is documented in the table on the right.
• PowerVM activation codes can be checked from the HMC, IVM, or from IBM records at this URL:
IBM Capacity on Demand: Activation code. The activation codes on the IBM web site will show up as type "VET" codes.
Express • Only available on limited lower-end P6 systems
• Maximum of 3 LPARs (1 VIOS and 2 VIOC)
• CPU Micro-Partitions with single processor pool
• VIOS/IVM only, no HMC support
• Dedicated I/O resources (in later versions)
Standard • Up to the maximum partitions supported on each server
• Multiple shared processor pools
• IVM or HMC managed
Premium • All options in Standard & Live Partition Mobility
• The VET codes from the IBM activation code web site can be decoded using the following "key":
XXXXXXXXXXXXXXXXXXXXXXXX0000XXXXXX Express
XXXXXXXXXXXXXXXXXXXXXXXX2C00XXXXXX Standard
XXXXXXXXXXXXXXXXXXXXXXXX2C20XXXXXX Enterprise