run vCenter in a VM: now it's best practice?

[marklemon]

This article:

http://searchvirtualdatacentre.techtarget.co.uk/news/column/0,294698,sid203_gci1512874,00.html?

says it's best practice.  It then goes on to raise a concern with the Update Manager.  I don't use update manager, so I'm interested in whether anyone can confirm and point me to which document from VMware says that vCenter is recommended to run on virtual machine as "best practice".

I am more willing to go that way than before, but I am still cautious when I consider complexities of failures.

If the ESX host running vCenter server completely failed, then, yes, vCenter would restart on another host.

But there are far more possibilities of problems than that.  What if the data store becomes unavailable?  What if the ESX host hangs with a problem that ties up the CPU? 

Being extremely cautious, I can't get away from the fact that virutalizing vCenter fundamentally means it having more complexity in the layers beneath it and therefore more possibilities for failure of the failover are introduced.

I know running vCenter on physical means that layer can still fail, but we're monitoring all our physical servers that run our ESX hosts. 

Putting a hypervisor on them doesn't prevent us from needing to deal with local disk/network/fibre channel/memory problems. 

searching VMware I found a doc that was written in 2009, not sure if it's still the latest gospel.  I'll raise a support call to ask VMware, but first wanted to see if you can give me a link to the answer.

http://communities.vmware.com/docs/DOC-11197

Interesting that this doc on VMware's site actually links back to the one on techtarget's site.  That's great, but I want the VMware reference that the techtarget article mentions.

cheers in advance for your time and help.

Generous points and enthusiastic kudos to anyone who can shed light here.

cheers,

Kevin

[AureusStone]

How can you ask people to put critical servers in an virtual environment, but then not trust it enough to put your management servers in it?

You are much more likely to have a failure on a physical rather then a virtual.  And if it dies you can rebuild a windows server and have vCenter up and running in no time.

This doesn't answer your question.  I am not sure about any VMWare documentation that says it is best practise, but I have seen it encouraged.

The following is from the install guide

~~~~~~~

Install vCenter Server in a Virtual Machine

You can install vCenter Server in a Microsoft Windows virtual machine, which runs on an ESX host.

Deploying the vCenter Server system in the virtual machine has the following advantages:

*     Rather than dedicating a separate server to the vCenter Server system, you can place it in a virtual machine
running on the same ESX host where your other virtual machines run.

*     You can provide high availability for the vCenter Server system by using VMware HA.

*     You can migrate the virtual machine containing the vCenter Server system from one host to another,
enabling maintenance and other activities.

*     You can create snapshots of the vCenter Server virtual machine and use them for backups, archiving, and
so on.

~~~~~~~~~~~~~~~

[NuggetGTR]

I think it really comes down to you design and if virtualising it is worth it.

I have not seen anything official saying virtualizing vcenter is prefered over a physical or its best practice, i think its more of a why not, can do it now maze well. and VMWare being in the business of virtualizing then im sure they would recommend it.

I have a mix of physical and virtual vcenter servers and i can say the virtuals ones are far easier to recover if there is an issue, just have to make sure you note down which host its on in large clusters. all the issues you mentioned can just as easily happen on a physical box, and nothing is stopping you monitoring a virtual vcenter server.

Personally i like the physical i know where it is i can touch it and if an ESX host dies its still up and kicking. but having worked with both and suffed failures with both i way prefer 5 - 10 minute recovery of a virtual vcenter server over sourcing a new physical restoring from backup etc.

[idle-jam]

if a vcenter hang due to pCPU then it would be automatically rebooted. now on the missing of datastore, there are always multipath and etc. even in a normal physical such risk occur too.

if you wanted 100% you can look into vmware vcenter heartbeat.

[MauroBonder]

Run  vcenter virtual machine is a good practice today, but some  specifications need to be configured as a preventive measure in case the  vcenter stay out.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=10087

http://www.vmware.com/pdf/vi3_vc_in_vm.pdf

[amvmware · Accepted solution]

The vSphere design course has this as best practise - the reasons have already been identifed. VMware's view is, a virtual vCenter server has levels of resilience and redundancy you may not necessarily have with a physical server or have to pay a significant premium to achieve, ie MS clustering.

It also gives you the flexibility to increase the resources - Disks, CPU and ram if you need to. Using a physical server you may hit physical capacity limitations.

If running it as aVM you need to use common sense - if you have one or two hosts then the risks may outway the benefits, ie a failure of one host leaves the Infrastructure dependent on the remaining host. If you have 10 hosts and a resilient storage solution then why not.

There is no wrong answer to the host environment for vcenter - no one ever got fired for running it on a physical server and the same can be said for virtual.

[habibalby]

vCenter in a VM is fully supported by VMWare. But I would say it also depends on your vCenter services, such as VMware-FT, or Distribution switches. When you are thinking of implementing these services and your vCenter is in a VM, then think of making your vCenter Highly available because these services are heavily depends on the vCenter.

Think of creating a MCSC cluster of vCenter on the local datastore of each host, so each vCenter Node will resides in the local datastore of the ESX Server.

[AndreTheGiant]

"Best practices" really depends on your environment and need.

But could be a recommended practice.

I've write this doc from my experience, but also from some doc that is not public available.

In the vSphere Design official course, the solution with a VM for vCenter (not necessary for all services, like DB and VUM) is recommended.

For large environment is suggested to use "management" cluster (with 3 nodes) for vCenter and all the management VMs.

Andre

[big_vern]

Would all of the comments still apply running it on ESXi host, I've  vague recollections of an instructor mentioning there was an issue running it as a VM on ESXi (as oppose to ESX) - something to do with HA?

[AureusStone]

Can't imagine it would make any difference.

I am running vCenter on ESXi.

[AndreTheGiant]

In the next vSphere version there will be only ESXi...

Only in first version of ESXi there were some difference in HA (for example was not recomended mix ESX and ESXi in same cluster)...

Andre