How HA & DRS will work on MSCS cluster.

[Kapil84]

Hi,

currently in my vSphere 5.0 environment I have 4 clusters.  One cluster  have 6 ESXi 5.0 host and on two of  the host I have build two Exchange Server VM using MSCS using RDM and rest  of 4 host host I am going to build 6 SQL servers using RDM.

So my question is can I enable HA and DRS on this cluster?

What things do I need to look out?

Regards,

KB

[weinstein5]

DRS: DRS will not work since configuration prevents the VMs form being vmotioned - so you would have to configure the VMs and have DRS disabled - 

HA: With HA enabled if there is a failure the VM will be restarted on another host in the cluster - If the VM is they standby node there should be no impact if it were the primary node the cluster will initiate a failover to the standby node - and when the primary returns you would be able to transfer the application back to the primary node -

[Kapil84]

Hi,

Thank you for quick response.

Ok so i need to enable HA on that cluster not DRS.

But  From the KB article 1037959 it shows that MSCS node limit 2. So it mean that HA will only work on two host not more than 2 host.

Link 1:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1037959

also in the Setup for Failover Clustering and Microsoft Cluster Service guide it mention multi host clustering is not supported , and HA will support maximum 2 node

link 2:

http://pubs.vmware.com/vsphere-50/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-50-mscs-guide.pdf

So please clarify me.  In my 6 host cluster will HA work for all VM those are running on each host?

just 2 VM which has configured with MSCS will that give a problem for my rest of VM running on different host?

if the exchange server VM which configure with MSCS  using RDM  running on one host goes down will that VM get restarted to another host or what?

Regards,

KB

[kjb007]

HA and MSCS are mutually exclusive.  MSCS on ESX is limited to two failover nodes in the MSCS cluster.  VMware HA has a limit of 32 nodes in the VMware HA cluster.

-KjB