ESX HA and MS Clustering

[elijah1]

We're installin a redundant configuratio in our remote office, consisting of 2 servers.

The idea is to cluster them on ESX level and 2 VMs running on it as an MS cluster.

What I'm trying to figure out is the following:

Scenario 1: Just use 2 physical boxes with shared storage and install MV Cluster on it. If one box fails - everything goes to the second one

Scenario 2: Have ESX on 2 hosts, configure 2 VMs on HOST1 and configure MS Cluster between those 2 VMs. If one VM fails it fails over to another VM with MS Clustering. If hardware on HOST1 fails then both machines are moved to the HOST2 and powered on there.

Scenario 3. 2 ESX hosts, VM1 runs on esxHOST1, VM2 runs on esxHOST2. If VM1 fails it goes to VM2 on host 2. If the esx1 on HOST1 fails the ehole thing goes on the second host.

Questions:

1. People here asking me why do we need ESX at all and I struggle to answer that - as without vMotion I don't see much point in having ESX HA

2, What are your though on the best-case HA scenarion here, providin that there will be no money allocated on DRS or vMotion.

Thanks.

Elijah.,

[geddam]

My vote is for MSCS for app/service level failovers. Best suited/proven for SQL servers in VMware environments.

VMware HA is good for VM level failovers.

These two cannot be compared as they both work in different ways.. Look for the jpg attached...

Thanks,,

Ramesh. Geddam,

VCP 3&4, MCTS(Hyper-V), SNIA SCP.

Please award points, if helpful

[kac2]

You are now independant of hardware. If by some chance that both physical servers failed and you had to restore from a backup, its difficult in the physical world. Where as you can take a set of VM files and power them on anywhere.

Another reason to go virtual is expansion. You are going to be using 2 servers dedicated to a single app. What happens 6 months down the line and they want a new server for App X? you could easily deploy a new VM instead of bringing in another server. That would be my rational behind going virtual.

Is this a server that needs to have zero downtime? MSCS is a pain IMO. If by some chance that the physical host did have a hardware failure, HA will reboot that VM on the other host. Leaving you with a few minutes of downtime.

also, vMotion and HA aren't the same thing. If money is no concern, you could go with Enterprise Plus licensing and just use Fault Tolerance. a single click to have a shadow copy running on another server in the cluster.

[elijah1]

Sorry, I'm really pressed in time - would you be able to give a quick overview in a human kanguage as to what ESX Fault tolerance is? And a hint how much it costs....

(I will read up on the internet as well)

[marcelo_soares]

If you have the two boxes and they will only allocated for this, I don't see any reason to virtualize them using ESX. I would go with scenario 1.

Now, if you are planning to use the boxes for something else than just this service, you are good doing 1 VM per ESX box, and clustering them with MSCS, OR you can use FT as described - this will demand a vSphere Enterprise license for both ESX and a vCenter license. Have in mind FT have several limitations like 1 CPU per VM and some other caveats. MSCS maybe the best option for you in this case.

Having both VMs of a MSCS cluster (scenario 2) on the same ESX, in this case, is a waste of time and deployment. You will rarely have a one VM problem to activate the MSCS cluster.

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[marcelo_soares]

You don't need enterprise plus for FT, you can go with the advanced or enterprise license ;-).

From: http://www.vmware.com/vmwarestore/vsphere_purchaseoptions.html

Marcelo Soares

VMWare Certified Professional 310/410

Virtualization Tech Master

Globant Argentina

Consider awarding points for "helpful" and/or "correct" answers.

[VMmatty]

I'm not sure how much this hurts your argument, but using MSCS in combination with VMware HA is unsupported by VMware. In order to maintain VMware support you need to manually exclude your MSCS VMs from HA.

I don't see the point in buying the ESX licenses to virtualize your cluster if all you plan to virtualize is that cluster. The limitations of VMware supportability make that a bad option. If you are planning on consolidating a bunch of servers and more heavily utilization virtualization in your organization then I think running MSCS on VMware is a great combo. You get the benefits of virtualization along with the application level awareness of a cluster.

Make sure you check the SVVP from Microsoft to ensure that you're operating a fully supported configuration if you plan to use clustering. Not all applications/OS versions are supported on VMware so you should check here before deciding whether or not to virtualize the cluster/application:

http://www.windowsservercatalog.com/svvp.aspx?svvppage=svvpwizard.htm