6.7

Table Of Contents
For a cluster of virtual machines on one physical host, all MSCS virtual machines must be in the same
virtual machine DRS group, linked to the same host DRS group with the affinity rule "Must run on hosts in
group."
For a cluster of virtual machines across physical hosts, all MSCS virtual machines must be in the same
virtual machine DRS group and all hosts must be in the same host DRS group. The virtual machine and
host DRS groups must be linked the affinity rule "Must run on hosts in group."
Caution Limit the number of hosts to two when you define host DRS group rules for a cluster of virtual
machines on one physical host. (This does not apply to clusters of virtual machines across physical
hosts.) Since vSphere HA does not obey VM-VM affinity rules, virtual machines in the configuration could
be spread across hosts during a vSphere HA recovery from host failure if more than two hosts are
included in a host DRS group rule.
Create a Virtual Machine DRS Group (MSCS)
Before you can create a VM-Host affinity rule, you must create the host DRS group and the virtual
machine DRS group that the rule applies to.
For both, a cluster of virtual machines on one physical host(CIB) and a cluster of virtual machines across
physical hosts(CAB), create one virtual machine DRS group that contains all MSCS virtual machines. For
example, VMGroup_1 contains MSCS_VM_1, MSCS_VM_2 … MSCS_VM_5.
Procedure
1 Browse to the cluster in the vSphere Client.
2 Click Configure.
3 Under Configuration, select VM/Host Groups and click Add.
4 In the Create VM/Host Group dialog box, type a name for the group.
5 Select VM Group from the Type drop down box and click Add.
6 Click the check box next to a virtual machine to add it. Continue this process until all desired virtual
machines have been added.
n
For a cluster of virtual machines on one physical host, add all MSCS virtual machines to one
group.
n
For a cluster of virtual machines across physical hosts, add all MSCS virtual machines to one
group.
7 Click OK.
Create a Host DRS Group (MSCS)
Before you can create a VM-Host affinity rule, you must create the host DRS group and the virtual
machine DRS group that the rule applies to.
Setup for Failover Clustering and Microsoft Cluster Service
VMware, Inc. 35