VMFarm Design Requirement

[rsaha]

Hi Guys,

I have following requirement from application team...

1. Require 8 VMs with 2VCPU and 8GB RAM each

2. Required 12 VMs with 4VCPU and 8 GB RAM each.

The following Software needs for the application : ASP.NET4 ;IIS,win 2K3/2008,SQL server 2005/2008 ,SAP NetWeaver etc.

We hv to design it on 2 physical host which will be in cluster.The host will be connected to DEV ,TEST and DMZ vlan as per application requirement.

Also FC SAN will be used for storing VMs

My Question..

1. Is it possible to go for a VMfarm?Becoz all VMs are using either 2 or 4 VCPU and we hv only 2 physical hosts.I believe it will slow down the performance very much

2. If possible how many esx host requird.Whats shd be the configuration of those hosts?Pls note,it will be on ESX3.5 env only.

3. Or is there any other way to design such requirement in virtual environment?

Waiting for Ur suggestions or practical experience in such env?

[DSTAVERT]

If you have current physical hosts to model the application workload I would start profiling these to get a better Idea of what the guests are actually using. Using static guesses at resource requirements is what we used in the physical world. That is one of the beauties of the virtual world in that you can tailor the resources to exactly what the guest needs. More often than not capacity is wasted by over committing unused resources.

Have a look at http://www.vmware.com/solutions/business-critical-apps/

3.5 is less capable of co scheduling multiple CPUs with this many multi CPU guests. 4.x would be a better choice. Very recent hardware with 6 or 8 core processors would also be a plus.

[Erik_Zandboer]

Hi,

I would never use only two hosts in a cluster. When one fails, the other has to run the full load. So when you are designing, you'd have to make sure all VMs can actually run on a single node. That would bring you to very heavy nodes indeed. It would even be more cost effective to get three or even four smaller nodes I guess: With four nodes, you only need to leave 25% resources free on the nodes instead of 50%, and that would suffice in case of a single host failing.

Like already said, Don't set out to configure VMs "because they say so" in a virtual environment. Very often, the VMs will not use their required specs by far.

It has always been a best practice to make sure a physical server always has more cores available than the largest VM has vCPUs. On top of that, in your proposed setup the VMs would have more vCPUs than physically available. There is nothing wrong with that, but if all VMs would decide to use 100% of their projected resources, you'd be in trouble. Luckily, in almost any environment that is never the case, and that is why VMware helps...

Personally I'd make sure to get nodes with Nehalem or better CPUs (E5500 or E5600 series), and configure all VMs with a single vCPU. Then increase memory and vCPUs as needed.

Visit my blog at http://www.vmdamentals.com

[rsaha]

Hi Guys,

Thanks a lot for your feedback

I can understand that using VSphere will be a better option but as the present env is esx3.5 and application team need to get the env for dev & Testing purpose urgently,so time is a factor.

Also i am thinking to use 3 node IBM BladeCenter HS22( 2 * 6 core CPU & 96GB RAM)

The total VCPU required: (28)+(412) =64VCPU

RAM : 20*8 = 160GB+ memory overhead

Using 3 node i will hv: RAM 963= 288 GB and Physical CPU 26)x3=36 Core.

Do u think it will work?

Waiting 4 ur suggestion.

[Erik_Zandboer]

It is hard if not impossible to guarantee that it will work 100%. On the other hand, the three nodes you state here are extremely versatile. I cannot imagine a set of test/dev VMs could ever get these nodes saturated. What storage is planned underneath?

Visit my blog at http://www.vmdamentals.com

[rsaha]

Storage: NetApp N7900

[rsaha]

The hosts need to be connected in dev/test vlan and DMZ as well.

Do u think is there any issue to configure DMZ on same host.

[Erik_Zandboer]

Don't have too much experience with NetApp, but that should work decent.

Mixing DMZ and OfficeLAN is done all the time; if you trust VLAN separation to be sufficient you can just insert dot1q trunks into the NICs. If the networks are separated physically, you'd have to insert the two network via different nics. I'd use a minimum of two uplinks per network to have redundancy and possibly some load balancing.

Visit my blog at http://www.vmdamentals.com