6.7

Table Of Contents
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MSCS on VVols can work with any type of disk, "Thin" as well as "Thick"-provisioned disks.
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This feature enables customers to move away from using Pass-through RDM (physical compatibility
mode).
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MSCS on VVols supports HA, DRS and vMotion.
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The underlying transport protocol can be FC, ISCSI or FCOE.
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Cluster-in-a-box (CIB) and a mixture of CAB and CIB is not supported.
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N+1 cluster configuration, in which one ESXi host has virtual machines which are secondary nodes
and one primary node is a physical box is not supported.
vSphere MSCS Setup Limitations
Before you set up MSCS, review the list of functions that are not supported for this release, and
requirements and recommendations that apply to your configuration.
The following environments and functions are not supported for MSCS setups with this release of
vSphere:
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Clustering on NFS disks.
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Mixed environments, such as configurations where one cluster node is running a different version of
ESXi than another cluster node.
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Use of MSCS in conjunction with vSphere Fault Tolerance (FT).
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Migration with vSphere vMotion
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of clustered virtual machines on a single host (CIB).
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N-Port ID Virtualization (NPIV)
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ESXi hosts that use memory overcommitment are not suitable for deploying MSCS virtual machines.
Memory overcommitment can cause virtual machines to stall for short durations. This can be
significantly disruptive as the MSCS clustering mechanism is time-sensitive and timing delays can
cause the virtual machines to behave incorrectly.
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Suspend or resume of more than one MSCS node in an ESXi host with a five-node cluster in a box
configuration is not supported. This I/O intensive operation is disruptive of the timing sensitive MSCS
clustering software.
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Storage spaces are not supported with Failover clustering on Windows 2012 and above.
MSCS and Booting from a SAN
You can put the boot disk of a virtual machine on a SAN-based VMFS volume.
Booting from a SAN is complex. Problems that you encounter in physical environments extend to virtual
environments. For general information about booting from a SAN, see the vSphere Storage
documentation.
Setup for Failover Clustering and Microsoft Cluster Service
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