LPAR

LPAR provides the most performant environment. It provides the core environment for all other environments since RHEL KVM and z/VM® are installed in LPAR. LPAR is a prerequisite when building clusters to host virtual machines with Red Hat® OpenShift® Virtualization. When high performance is required, LPAR is a good choice. Management is done directly through the hardware management console (HMC) and is simplified by providing fewer management options. The downside is the reduced flexibility that hypervisor environments provide. Furthermore, each machine supports a maximum of 40 or 85 LPARs. This limitation restricts the number of cluster nodes, which can affect some use cases.

Resource sharing

Resources of the system can be shared among LPARs. The resources of one LPAR are then shared among the pods that run on the LPAR. Each LPAR can be set up to efficiently share resources like CPU, network, storage IO cards, and crypto and use them optimally. But it is also possible to dedicate those hardware resources if required.

Cluster HA/DR

Cluster HA/DR is based on Red Hat OpenShift mechanisms like backups via Velero or connecting clusters via Submariner. It is important to consider IBM® Storage Server concepts like FlashCopy and making passive cluster resources available. For more information about these topics, see the cluster HA/DR section.