Merge pull request #59924 from bburt-rh/RHDEVDOCS-3241-document-no-NFS-support-for-PVC

RHDEVDOCS-3241: document-no-NFS-support-for-PV-for-Prometheus

Author: bburt-rh

modules/monitoring-configuring-persistent-storage.adoc

@@ -20,4 +20,11 @@ Running cluster monitoring with persistent storage means that your metrics are s
 [NOTE]
 ====
 If you use a local volume for persistent storage, do not use a raw block volume, which is described with `volumeMode: Block` in the `LocalVolume` object. Prometheus cannot use raw block volumes.
+====
++
+[IMPORTANT]
+====
+Prometheus does not support file systems that are not POSIX compliant.
+For example, some NFS file system implementations are not POSIX compliant.
+If you want to use an NFS file system for storage, verify with the vendor that their NFS implementation is fully POSIX compliant.
 ====