Managing classic virtual system instances

Classic virtual system instances are created by using patterns that are composed of parts that are provided in your virtual images. The pattern is deployed to your hypervisors based on a component of Cloud Pak System called placement. The placement component is an internal component that performs the job of deciding which hypervisors to use when virtual machines are deployed. The placement component is also used when an existing classic virtual system instance is extended by adding virtual machines. It uses a complicated algorithm that considers a number of properties of the environment. For example, it considers the properties of the physical machines, existing classic virtual system instances on the hypervisors, and virtual machines on the hypervisor that are not managed by Cloud Pak System. The properties of the classic virtual system instances being deployed or extended are also considered during placement decisions. Most notably, the placement component considers the memory, physical CPUs, network addresses, disk space, and disk image sharing on the hypervisor. The placement component is part of the product code and is not configurable.

Besides determining where virtual machines are deployed, the placement component also performs the job of deciding whether to permit a specific classic virtual system instance deployment. The product licenses can be counted when Cloud Pak System is configured to enable license tracking. Use this configuration to prevent the number of deployments from exceeding your maximum allowed number of licenses. For more information about license management options, see Administering product licenses.

The classic virtual system instances are managed by Cloud Pak System and can be serviced and accessed through the console. Classic virtual system instances managed by Cloud Pak System are dynamic. Virtual machines can be added or removed to allow your virtual systems to scale based on current demand. You can increase the capacity of your virtual machines to scale for increased user demands by creating clones of existing virtual machines. If needed, you can scale down the environment and remove unnecessary virtual machines.

If you plan to use the Database Performance Monitoring shared service, ensure that you have ports available to use on any classic virtual system instances . Ports must be reserved for any DB2® databases that are running as virtual applications when you configure classic virtual system instances. This port number is set when a DB2 instance is installed in a virtual system.

For more information about operating system agents, services, and daemons that run in classic virtual system instances, refer to the documentation for the operating system.