A protection domain (PD) is a group of nodes or storage data servers that provide data isolation, security, and performance benefits. A node participates in only one protection domain at a time. Only nodes in the same protection domain can affect each other, nodes outside the protection domain are isolated. Secure multitenancy can be created with protection domains since data does not mingle across protection domains.
You can create different protection domains for different node types with unequal performance profiles. All the hosts in the domain must have the same type and configuration. A PowerFlex hyperconverged node should not be in the same protection domain as a PowerFlex storage-only node. The node configuration must match, which includes the drives, CPU, and memory. Any difference in the node configuration leads to an unknown performance impact. We configured a single protection domain for the 5 nodes that included all 120 SSD drives.