VMware/Microsoft doesn’t support third-party multipathing or the Round Robin path policy for VMs setup in a Microsoft Failover Cluster. This fact is stated in the “Setup for Failover Clustering and Microsoft Cluster Service” PDF on pages 11, 25 and 36 http://www.vmware.com/pdf/vsphere4/r40_u1/vsp_40_u1_mscs.pdf
The reason why this isn’t supported is due to the way the SCSI-3 command sets are changed when the NMP (Native Multipathing Plugin) Round Robin is set or when third-party multipathing software (EMC PowerPath VE) is installed.
If you try to create a cluster on an ESX host with either of these the Microsoft cluster validation check will fail on the SCSI-3 Persistent Reservation check.
If you need to run a Microsoft Cluster on a host with PowerPath VE installed you can modify the claim rules so that PowerPath VE doesn’t claim the LUNs that the cluster will be using.
Lets say for example the LUNs the Microsoft cluster will be using are LUNs 12 – 14. To modify the claim rules using the ESX COS CLI run these commands
To list the current claim rules run
esxcli corestorage claimrule list
To add claim rules that force the Microsoft cluster LUNs to be owned by the NMP (Native Multipathing Plugin) run these commands
esxcli corestorage claimrule add –rule=210 –plugin=”NMP” –lun=12 –type=”location”
esxcli corestorage claimrule add –rule=211 –plugin=”NMP” –lun=13 –type=”location”
esxcli corestorage claimrule add –rule=212 –plugin=”NMP” –lun=14 –type=”location”
esxcli corestorage claimrule load
esxcli corestorage claimrule run
NOTE – The rule number must be between 201 and 249
Run esxcli corestorage claimrule list to verify the new rules were added.
You can also use the VMware vSphere CLI 4 from a remote machine or the VMware vSphere Management Assistant (vMA). When running esxcil from either of these the commands will look like this.
esxcli –server=esxhostname –username=root corestorage claimrule add –rule=210 –plugin=”NMP” –lun=12 –type=”location” corestorage claimrule add –rule=210 –plugin=”NMP” –lun=12 –type=”location”
esxcli –server=esxhostname –username=root corestorage claimrule add –rule=211 –plugin=”NMP” –lun=13 –type=”location” corestorage claimrule add –rule=210 –plugin=”NMP” –lun=12 –type=”location”
esxcli –server=esxhostname –username=root corestorage claimrule add –rule=212 –plugin=”NMP” –lun=14 –type=”location” corestorage claimrule add –rule=210 –plugin=”NMP” –lun=12 –type=”location”
esxcli –server=esxhostname –username=root corestorage claimrule load
esxcli –server=esxhostname –username=root corestorage claimrule run
esxcli –server=esxhostname –username=root corestorage claimrule list
Jeremy Waldrop's Blog 