A customer highlighted their interest in the node filesystem for OpenShift versions 4.18 and 4.20. Upon further investigation, it was found that 4.18 nodes are using XFS, whereas 4.20 nodes are using ComposeFS. This information is not mentioned in the official release notes.

Additional context/reference: https://redhat.enterprise.slack.com/archives/C999USB0D/p1748431240817979

Please confirm if this filesystem information is documented in the release notes.

Note the fix in https://access.redhat.com/errata/RHSA-2025:13848 which is mentioned here in 4.19: https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/release_notes/ocp-4-19-release-notes#ocp-4-19-9-bug[…]_release-notes
But still there is nothing mentioned specifically for file system.