…if I buy the additional processor activations and license Keys for that system?
If those are available to you, I suppose it’s possible. But then it wouldn’t be a CBU any more.
That is, I would effectively think of it as being the purchase of an upgrade. I have no idea if there are order/feature codes for that. I don’t know if anyone has ever wanted to do it before. It’s hard to think that it would be inexpensive.
The BP is probably the only one who could answer if anyone can. (Even the IBM license group can be unclear about how to handle CBUs.)
Maybe you’ll be lucky and someone who’s tried it can respond.
The advantage of a CBU cost comes into play in that the software licenses are Paired to your primary box, so you only pay for 1 OS enablement and remaining OS and LPPs in most cases are no cost for the CBU machine. IBM has several rules for this both in sizing of the CBU machine itself and how it is used. The term CBU is more a licensing structure used by IBM to describe the pricing for a Disaster Recovery machine with more attractive software pricing.
We have a machine that serves several purposes. Hardware configured with 2 independent partitions on a E4B. Partition one has own disk controller, comm adapter, 2 unshared processors running OS 6.1 serving as a CBU for our data center we had to pay license on first OS, second OS and LPPs are paired with our Data Center machine. The second partition has the remaining 6 processors configured shared, uncapped to date with 6 OS 7.1 LPARs running under it. Had to pay for 6 OS entitlements. Bottom line is you cannot use the CBU OS or LPP entitlements for anything other that for a Disaster Recovery machine. Paying for them, as Tom says, is the same as running Disaster Revovery on a fully licensed machine. It would also be quite an experience to try to relicense a CBU machine, since they are paired from the factory.