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

--> Because Prometheus has two replicas and Alertmanager has three replicas, you need five PVs to support the entire monitoring stack.

Section Number and Name: 
Persistent storage prerequisites

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.

Additional information: