VMware Cloud on AWS supports SCSI-3 Persistent Reservations for workload VMs. You need to use this capability when configuring a Windows Server Failover Cluster (WSFC) in your SDDC.

Most of what you need to know to configure workload VMs to support WSFC is explained in About Setup for Windows Server Failover Clustering on VMware vSphere in the vSphere Product Documentation. This topic adds a few steps that you'll need to follow if you want to configure WSFC to use the vSAN storage in your SDDC.

VMware Cloud on AWS supports WSFC on both conventional and stretched clusters.

A Windows Server Failover Cluster uses SCSI-3 Persistent Reservations to arbitrate shared access to clustered disk resources. To make this work, VMs in the cluster must meet several configuration requirements:
  • To enable use of SCSI-3 Persistent Reservations , shared disks must be accessed through a SCSI controller with SCSI Bus Sharing set to Physical.
  • To prevent unsupported snapshots operations on the shared disks, the Disk Mode of all disks in the cluster must be set to Independent – Persistent.
In a VMware Cloud on AWS SDDC, vSAN supports SCSI-3 Persistent Reservations on up to six application nodes per guest cluster with up to 64 shared disks.

Note:

When a VMDK is shared using SCSI-3 Persistent Reservations, VM operations such as snapshots, storage vMotion to or from a vSAN datastore, cloning, hot extension of a hard disk, and replication through vSphere Replication are not supported. See VMware Knowledge Base article 79616 for a detailed discussion of supported configurations.

You must not enable VMDK multi-writer on WSFC disk resources.

For a thorough discussion architectural guidelines and detailed stepwise procedures for configuring and migrating WSFC workloads on VMware Cloud on AWS, see the VMware Technical Article Microsoft SQL Server Workloads and VMware Cloud on AWS: Design, Migration, and Configuration and the VMware blog post Native SQL Server Cluster support on vSAN.

Procedure

  1. Configure the first node in the cluster.
    Follow the steps in Add Hard Disks to the First Node for Cluster Across Physical Hosts with Clustered VMDKs on VMFS Datastores with these additions:
    1. Set the Disk Mode to Independent – Persistent.
    2. (Optional) Assign the disk a custom VM storage policy.
      While not a requirement, it's likely that any data that you need to protect with WSFC would benefit from having a dedicated storage policy.
  2. Configure additional nodes.
    Follow the steps in Add Hard Disks to Additional Nodes for Clusters Across Physical Hosts with these additions:
    1. Set the Disk Mode to Independent – Persistent.
    2. (Optional) Assign the disk a custom VM storage policy.
  3. Use the Microsoft Create Cluster Wizard to validate the cluster.
    Note:

    During validation, the wizard displays a warning in the category Storage and subcategory Validate Storage Spaces Persistent Reservation. This warning is not applicable when configuring a Windows Server Failover Cluster in your SDDC and can be safely ignored.