Two BZs addressing: https://docs.openshift.com/container-platform/4.10/monitoring/configuring-the-monitoring-stack.html#persistent-storage-prerequisites

BZ bug link on the Jira field is for the oldest bug, but both BZs should be closed when this issue is addressed. 

• https://bugzilla.redhat.com/show_bug.cgi?id=2080367
  • Describe the issue:
    on the relase notes for OCP 4.10 we got on Added hard anti-affinity rules and pod disruption budgets for certain components alertmanger note:
    • " As part of this change, the number of Alertmanager replicas has been reduced from three to two"
    • and on the documentation of PVC for Alertmanager we got: "Because Prometheus has two replicas and Alertmanager has three replicas"
    • Suggestions for improvement:
      Change the text to:
      "Make sure you have a persistent volume (PV) ready to be claimed by the persistent volume claim (PVC), one PV for each replica. Because Prometheus and Alertmanager has two replicas each, you need four PVs to support the entire monitoring stack. The PVs should be available from the Local Storage Operator. This does not apply if you enable dynamically provisioned storage.
• https://bugzilla.redhat.com/show_bug.cgi?id=2105935 
  • Describe the issue:
    In OCP 4.10, the number of Alertmanager replicas has been reduced from three to two, so the statement "Because Prometheus has two replicas and Alertmanager has three replicas, you need five PVs to support the entire monitoring stack." is not correct anymore. Please refer to the following release note.https://docs.openshift.com/container-platform/4.10/release_notes/ocp-4-10-release-notes.html#ocp-4-10-monitoring-added-hard-anti-affinity-rules-and-pod-distruption-budgets
    --> Alertmanager
    • As part of this change, the number of Alertmanager replicas has been reduced from three to two.
    • Suggestions for improvement:
      Modify the statement to meet the correct number of Alertmanager replicas in OCP 4.10.