Support Policies for RHEL High Availability Clusters - Storage Compatibility

Contents

• Overview
  • Applicable Environments
  • Useful References and Guides
  • Introduction
• Policies

Overview

Applicable Environments

• Red Hat Enterprise Linux (RHEL) with the High Availability Add-On
• Some form of shared storage device presented to nodes within a cluster

Useful References and Guides

• Support Policies for RHEL High Availability clusters

Introduction

This policy guide describes general requirements and limitations as they relate to storage devices used by any RHEL High Availability cluster. Users of RHEL High Availability clusters should adhere to these policies in order to be eligible for support from Red Hat with the appropriate product support subscriptions. Other storage-related policies may apply to individual components or features and thus may be detailed in individual policy guides specific to those components.

Policies

No certification of 3rd-party storage solutions: Red Hat does not certify other vendors' storage solutions for compatibility with the RHEL High Availability cluster components. Red Hat does not guarantee compatibility or support coverage for usage of any particular storage solution, and will use its own discretion in pursuing features or compatibility with any particular storage technology.

It is recommended that organizations thoroughly test all deployments to establish whether behavior from all involved components of a High Availability deployment is as expected and raises no concerns. If any such concerns exist, it is recommended that Red Hat Support be engaged to determine whether the findings will affect the supportability or behavior of clusters using the storage devices in question.

Storage/data replication: Cluster deployments interacting with storage or data that is replicated in some way presents additional challenges and considerations that may have an impact on behavior of the cluster or its resources in some cases. When a cluster is known to have such replication in its design and there is a suspicion it could contribute to a concern being investigated, Red Hat Support may request reproduction or diagnosis of the incident without the usage of this replication method.

Write access to shared storage for cluster nodes only: Red Hat does not recommend providing direct access to cluster-shared block storage to any systems outside the cluster. In any environment where such outside-sharing is known to be present, Red Hat may require reproduction or diagnosis of the concern with access by the outside system disabled.

No MD-raid with shared devices: Red Hat will not provide support for concerns relating to a cluster's usage of MD-raid devices consisting of block devices shared throughout the cluster. Such devices present risks and challenges in ensuring data coherency and protections when shared throughout a cluster. Concerns raised to Red Hat Support in a cluster environment using such a configuration may require reproduction or diagnosis of the concern without such MD-raid configurations involved in order for the engagement to continue. For more information then see: Can pacemaker manage software raid devices?