OpenShift Container Platform 4.21 and 4.22 introduce two major node resource management changes. First, AutoSizingReserved is now enabled by default for new clusters in 4.21, automatically calculating CPU and memory reservations for system daemons based on node capacity using tiered formulas. Second, system-reserved-compressible enforcement arrives in 4.22, using cgroup v2 controls to enforce CPU limits on system daemons via the systemd system.slice cgroup. Existing clusters upgrading from 4.20 are protected by an automatically applied MachineConfig that keeps auto-sizing disabled until administrators explicitly opt in. Detailed memory and CPU reservation formulas are provided, along with verification commands and compatibility notes for performance profiles.
