Oracle VM Server for SPARC software enables you to create and manage logical domains (also known as guest domains). You can virtualize resources and define network, storage, and I/O devices as services that can be shared between guest domains. The Oracle VM Server for SPARC configurations are stored on the SP. You can add a configuration, specify a configuration to be used, and list the configurations on the SP.
The number of logical domains you can create depends on the hardware configuration of the server. By default, one domain, the primary domain (also known as the control domain), is configured when you install the OS on a host. The primary domain cannot be removed or renamed, and all of the resources are assigned to the primary domain when the domain is configured. The primary domain should have at least one or two CPU cores and 16 to 64 GB of memory to operate properly. You can have as many as 128 guest domains per physical domain (also known as a PDomain), and each guest domain can operate on only one CPU thread. However, most workloads require more than one CPU thread.
For high-RAS configurations, you should align guest domains on core boundaries to avoid issues that can occur when two or more guest domains share threads from a single core. Aligning the guest domains on core boundaries does affect the total number of guest domains that you can create. In addition, the primary domain should retain at least one or two cores to operate properly and to isolate it from any other guest domain.
Nevertheless, the number of available cores, the amount of available memory, and the number of available PCIe slots also affect the total number of possible guest domains. For more information about assigning resources to guest domains, see the following:
Oracle VM Server for SPARC Best Practices white paper at http://www.oracle.com/technetwork/server-storage/sun-sparc-enterprise/documentation/whitepapers-2158892.html.