6.1

Protecting Microsoft Cluster Server and Fault Tolerant Virtual
Machines
You can use Site Recovery Manager to protect Microsoft Cluster Server (MSCS) and fault tolerant virtual
machines, with certain limitations.
To use Site Recovery Manager to protect MSCS and fault tolerant virtual machines, you might need to
change your environment.
General Limitations to Protecting MSCS and Fault Tolerant Virtual Machines
Protecting MSCS and fault tolerant virtual machines is subject to the following limitations.
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You can use array-based replication only to protect MSCS virtual machines. Protecting MSCS virtual
machines with vSphere Replication is not supported.
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Reprotect of MSCS or fault tolerant virtual machines requires VMware High Availability (HA) and
VMware Distributed Resource Scheduler (DRS). When you move MSCS or fault tolerant virtual
machines across their primary and secondary sites during reprotect, you must enable HA and DRS, and
set the affinity and antiaffinity rules as appropriate. See “DRS Requirements for Protection of MSCS
Virtual Machines,” on page 130.
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Site Recovery Manager does not support multiple vCPU fault tolerance (SMP-FT) virtual machines.
ESXi Host Requirements for Protection of MSCS Virtual Machines
To protect MSCS or fault tolerant virtual machines, the ESXi host machines on which the virtual machines
run must meet certain criteria.
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You must run a fault tolerant virtual machine and its shadow on two separate ESXi Server instances.
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You can run a cluster of MSCS virtual machines in the following possible configurations.
Cluster-in-a-box
The MSCS virtual machines in the cluster run on a single ESXi Server.
You can have a maximum of five MSCS nodes on one ESXi Server.
Cluster-across-boxes
You can spread the MSCS cluster across a maximum of five ESXi Server
instances. You can protect only one virtual machine node of any MSCS
cluster on a single ESXi Server instance. You can have multiple MSCS
node virtual machines running on an ESXi host, as long as they do not
participate in the same MSCS cluster. This configuration requires shared
storage on a Fibre Channel SAN for the quorum disk.
DRS Requirements for Protection of MSCS Virtual Machines
To use DRS on sites that contain MSCS virtual machines, you must configure the DRS rules to allow
Site Recovery Manager to protect the virtual machines. By following the guidelines, you can protect MSCS
virtual machines on sites that run DRS if the placeholder virtual machines are in either a cluster-across-
boxes MSCS deployment or in a cluster-in-a-box MSCS deployment.
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Because vSphere does not support vSphere vMotion for MSCS virtual machines, you must set the VM to
Host DRS rule so that DRS does not perform vMotion on MSCS nodes. Set the VM to Host rule for the
virtual machines on the protected site and for the shadow virtual machines on the recovery site.
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Set the DRS rules on the virtual machines on the protected site before you configure MSCS in the guest
operating systems. Set the DRS rules immediately after you deploy, configure, or power on the virtual
machines.
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Set the DRS rules on the virtual machines on the recovery site immediately after you create a protection
group of MSCS nodes, as soon as the placeholder virtual machines appear on the recovery site.
Site Recovery Manager Administration
130 VMware, Inc.