Oracle Licensing for Virtual Environments
It's generally better, from a licensing perspective, to have fewer, faster cores, and scale by adding servers, rather than buying servers with more cores.
Buying multiple Oracle licenses in a single transaction generally yields a higher level of discount but does limit the ability to reduci annual cost by reducing cores and cancelling the Oracle support contract for those cores.
If you know your application has a limited life, consider term licenses to reduce initial cost and more readily realise cost savings on support later. But note that this is not cost effective if you need to buy a new term license each time the current license expires.
Hardware Partitioning
AKA Server Partitioning or Segmenting.Hard Partitioning
Each separated system acts as a physically independent, self-contained server, typically with its own CPUs, operating system, separate boot area, memory,input/output subsystem and network resources (1)Soft Partitioning
Not permitted as a means to determine or limit the number of software licenses required for any given server or cluster of servers (1)Sun Physical Domains
Solaris Zones
Oracle Trusted Partitions
IBM LPAR
IBM micro-partitions
HPE vPar
HPE nPar
Integrity Virtual Machine
Secure Resource Partitions
Fujitsu PPAR
Oracle VM (OVM)
Oracle KVM
VMWare vSphere
Solaris 9 Resource Containers
IBM AIX Workload Manager (WPAR)
HP Resource Manager
Affinity Management
Exceptions
Using IBM processors in TurboCore mode is not permitted as a means to reduce the number of software licenses required; all cores must be licensed. (1)
IBM Power VM Live Partition Mobility is not an approved hard partitioning technology. All cores on both the source and destination servers in an environment using IBM Power VM Live Partition Mobility must be licensed. (1)
Oracle Linux KVM can be used as hard partitioning if specific cores are allocated.
Oracle VM Server for x86 can be used as hard partitioning if specific cores are allocated.
Oracle VM Server for SPARC can be used as hard partitioning if specific cores are allocated.
Capacity On-Demand
(Pay As You Grow)Oracle allows customers to license only the number of cores that are activated when the server is shipped. (1) (where this is technically possible)
You can activate, and license, additional cores later, but you cannot reduce license requirement by disabling them.
Capacity on Demand is also available on certain Oracle Engineered Systems. (1)
RAC
Note that VMWare does NOT currently (Jun-2023) appear on the list of "Certified Virtualization and Partitioning Technologies for Oracle Database and RAC Product Releases - Unix, Linux, & Windows Operating Systems" (Oracle virtualization-matrix)