VMware

This Question is Possibly Answered

1 "correct" answer available (10 pts) 2 "helpful" answers available (6 pts)
3 Replies Last post: Nov 9, 2009 9:14 AM by AndreTheGiant  

one cluster or two? posted: Nov 6, 2009 6:58 PM

Click to view russ79's profile Novice
russ79
11 posts since
Nov 4, 2008

in a nutshell my current enviornment:

  • 1 Intel Cluster of 5 hosts (core 2 and i7) for production, attached to production san
  • 1 Intel Cluster of 2 hosts (core 2) for development, attached to development san
  • 4 Standalone Intel hosts (core 2) some for production, some for development
  • 6 Standalone AMD hosts (older opteron) for development

I am beginning the process of upgrading to vSphere and I've made the suggestion of pooling all of our Intel boxes into 1 cluster on the production san. We have enough capacity to retire our AMD boxes. I could use resource pools and vlans to keep production and development VMs separated. I am looking for any thoughts and comments on this plan. I think this might be a good idea but i'm curious to know if anyone thinks otherwise.

Re: one cluster or two?

1. Nov 6, 2009 11:46 PM in response to: russ79
Click to view AndreTheGiant's profile Guru
AndreTheGiant
5,897 posts since
Aug 28, 2008
There is a tradeoff between a lot of nodes into a cluster and few (but enogh) nodes...
With too many nodes you have some capacity problems for admission control.
With too much the cluster could be a little slower.
Also too much nodes on the same LUNs could be not the best choice.

IMHO I suggest to use cluster with 4-6 nodes.

Andre

Re: one cluster or two?

2. Nov 7, 2009 11:39 AM in response to: AndreTheGiant
Click to view russ79's profile Novice
russ79
11 posts since
Nov 4, 2008

Andre,

Can you describe what kind of admission control problems would arise? Have you had any experience with clusters greater than 6 nodes that makes you pick 4-6 as an optimum number? I know the max is 32 nodes per cluster, I wont be going anywhere near that number, I fully understand the issues that could arise from too much I/O on a lun and in fact this cluster would be using 3 to 4 different luns with no extents...

-Russ

Re: one cluster or two?

3. Nov 9, 2009 9:14 AM in response to: russ79
Click to view AndreTheGiant's profile Guru
AndreTheGiant
5,897 posts since
Aug 28, 2008
Can you describe what kind of admission control problems would arise?
Less nodes = more resources problem when you have a fail

Have you had any experience with clusters greater than 6 nodes that makes you pick 4-6 as an optimum number?
With ESX 3.5 a good number is 5 (the max number of primary nodes). On ESX 4.0 this number is not so important, but the I/O problem and the number of ESX that insist on the same LUN can give a max realistic number smaller than 32.

For more info on how HA works:
http://www.yellow-bricks.com/2008/09/09/ha-primary-and-secondary-nodes/

Andre

Actions

VMware Developer

SDKs, APIs, Videos, Learn and much more in the Developer community.

Learn More

Developer Sample Code

Increase your developer productivity with VMware API sample code.

Learn More

VMworld Sessions & Labs

Online access to the latest VMworld Sessions & Labs and online services.

Learn more

Purchase PSO Credits Online

Purchase credits to redeem training and consulting services online.

Buy Now

Community Hardware Software

View reported configurations or report your own.

Learn More

VMware vSphere

Come witness the next giant leap in virtualization.

Register Today

Communities