Jason Boche is definitely going for that top ten blogs lists by Eric Siebert. Jason has been releasing high quality blogs over the last couple of week, keep it up!
I just noticed his latest addition:”
Make VirtualCenter highly available with VMware Virtual Infrastructure“. Which is a great article on the advantages of virtualizing your VirtualCenter server. Jason wasn’t the only one that picked up this “trend”, so did this “newcomer” and colleague Dave Lawrence aka VMGuy. (Newcomer in the blogosphere.)
Like always I’ve got my own view on making VirtualCenter, or should I say vCenter, highly available. I fully agree with both gents to use the VirtualInfrastructure technology to achieve this. I’m no big fan of Microsoft Clustering Services for this purpose.
When virtualizing VirtualCenter remember a couple of things:
- Disable DRS(Change Automation Level!) for your VirtualCenter VM and make sure to document where the VirtualCenter server is located (My suggestion would be the first ESX Box)
- Enable HA for the VirtualCenter server, and set the startup priority to high
- Make sure the VirtualCenter server gets enough resources by setting the shares “high”, and maybe even set reservations
- Make sure VirtualCenter starts up automatically when a power cut occurs (Configuration, Virtual Machine Startup and Shutdown)
- Make sure other services and servers that VirtualCenter relies on are also starting automatically, with a high priority and in the correct order like:
- Active Directory
- DNS
- SQL
- At Least 2GB of Memory and 1 CPU
I know most of these best practices are documented here and pretty obvious, but somehow they are often overlooked. Especially number 1,4 and 5. Why are these important?
Well when a complete site fails, which will be a stressful situation, you don’t want to spend time looking on every single ESX host if the VirtualCenter was located there before the power cut. With DRS enabled it can and probably will be vmotioned around the environment and you need to start it from the command line with “vmware-cmd” when for some reason HA or the automatic startup fails. This can only be done on the host where the VM was located before the power cut / isolation.
So again, I do advise to virtualize your VirtualCenter Server, but make sure you know where the VirtualCenter Server resides at all time and write procedures for booting the environment manually!
Lane Leverett says
Hey Duncan,
Thanks for fleshing this out a bit more than I had on my reply to Jason’s original article on MSCS clustering for vCenter (I guess I’m gonna have to get used to that name). ; ‘ )
I think you have it right on track for all the settings you mentioned in order to ensure vCenter’s high availability and the ability to find the vCenter vm in case something goes wrong and it doesn’t come up. But for larger environments I have been recommending that customers actually setup a separate management cluster of two hosts. These hosts can be scaled down quite a bit from a typical ESX cluster host. What I would then run on that separate cluster is all my management VMs (vCenter, separate SQL VM for vCenter and Update Manager, a VM for Update Manager, SRM, VDM Connection Brokers, etc. Then we are able to make use of all the wonderful features of HA/DRS/Vmotion for all of the different management applications that are seeming to proliferate in the past couple of years. But since this is now just a two host cluster it is much easier to be able to find where vCenter lives. You have a 50/50 chance of getting it right on the first try. Just a different way to go about it, and not the right solution for all environments (especially really small shops).
Larry Passo says
I would leave DRS enabled but configure a custom automation mode for the VM that has VC installed. The custom automation mode should be set to disabled. That way DRS will not move that VM but the rest of your cluster can take advantage of DRS.
See page 114:
http://www.vmware.com/pdf/vi3_301_201_resource_mgmt.pdf
Duncan Epping says
That’s what I meant to say Larry, just badly worded it.
Virtual_JTW says
I don’t fully agree with the first recommendation assuming VMs are being tracked as I think should done anyway. See – http://communities.vmware.com/blogs/ManualAutomation/2008/11/24/virtualizing-virtual-center-revisisted for more info.
Duncan says
if you track your vm’s than it shouldn’t be a problem indeed… if you track your vm’s. if.