How many nodes in a cluster would you add ?

[vcpguy]

Folks, I wanted your opinion regarding the number of hosts in the cluster.

I have 8 ESX boxes. I can either create 1 big cluster and make all the 8 hosts part of the cluster

OR

I can create 2 FOUR node clsuter.

What would u all do ?

[weinstein5]

First thing all the CPUs in all 8 boxes compatible so that you could set up a DRS cluster - DRS relies on vmotion so the requirements for vmotion need to be met - if they are I would consider an 8 node cluster and use reqource pools to carve up for different user groups -

[curriertech]

What will your shared storage configuration be? That would play a big part, if I was facing the same decision.

-Josh.

[Erik_Zandboer]

if your hosts are compatible (CPU types especially) and all hosts have access to shared storage, I would always go for one big cluster. Otherwise, sort your hosts to vmotion compatible hosts, and create a cluster for each group. If you end up with a single host, do not put that one in a cluster at all (big lonely otherwise ).

You could also think about upgrading your CPUs to match them, or possibly use EVC to smoothen out you CPU features and make them vmotion compatible.

[malaysiavm]

You can expand more if possible, to ensure EVC enable and your VM network configuration name is consistent. That will provide more capacity for failover related

Malaysia VMware Communities -

[ChrisDearden]

provided your storage is up to it & as mentioned you are running vmotion compatable CPU's then 1 big cluster is the way to go.

if you were to allow 1 host failure , then you coudl only load each node in a 4host cluster upto 75% . you can load an 8 node cluster to a higher level.

[Texiwill · Accepted solution]

Hello,

The size of a cluster depends on the storage environment more than anything. If you have an entry Level SAN it may be able to handle all 8 Nodes attached to the same LUNs with no issues. In some cases I have seen only 4 nodes per LUN tax a remote storage device. If you have any high end Storage equipment then its not an issue. If you have entry level then it could be. You need to look for SCSI Reservation Conflicts on your storage if you see any when you are not doing anything but running VMs (ie. no metadata changes) then you have pushed the storage past where it can safely go.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

CIO Virtualization Blog: http://www.cio.com/blog/index/topic/168354

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[vcpguy]

I have a DMX box and CX3-80. I dont think that should be a issue right ?

[Texiwill]

Hello,

Depends on the configuration of the DMX, but in general no. I would combine all 8 nodes then monitor you may find you have to take a node out or you may find it is perfectly fine.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

CIO Virtualization Blog: http://www.cio.com/blog/index/topic/168354

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[azn2kew]

I would use all 8 hosts in a cluster and configure 7 hosts + 1 for failover capacity such as N+1 model. Also you have more choices to allow ESX failure in the DRS settings. If you have 4 ESX hosts in a cluster, you might only allow 1-2 ESX failured. But if you have 8 in a cluster, you can allow maximum 4 host failures but that will not likely to happen all at once. That's pretty much the advantage I can see from here.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant

[williambishop]

Keep in mind growth however. We originally went with 8 nodes per cluster, then found 4 nodes fit our needs better(no issues with san though, our dmx easily did 8). But we found that our intended environment grew faster than we expected, and it became easier to provision in 4 node groups. As with everything, IT DEPENDS...That said, as others stated, you shouldn't have any issues.