Comments on: Virtualizing vCenter With vDS Catch-22

By: Design Challenges Of Virtualized vCenter With A vNetwork Distributed Switch – Gestalt IT

Mon, 22 Mar 2010 18:29:33 +0000

[...] Virtualizing vCenter With vDS Catch-22 is another post that explores what happened after taking down the vCenter VM for a routine migration. “vCenter was shut down and unavailable, therefore, I had connected my vSphere client directly to the ESX4 host in which I transferred the VM to. When trying to configure the vCenter VM to use the vNetwork Distributed Switch (vDS) port group I had set up for all VM traffic, it was unavailable in the dropdown list of networks. The vCenter server was powered down and thus the vDS Control Plane was unavailable, eliminating my view of vDS networks. [...]

By: VM’s can’t ping while on Distributed Virtual Switching VLAN’s « TheSaffaGeek

Mon, 08 Mar 2010 13:04:31 +0000

[...] http://www.boche.net/blog/index.php/2009/10/09/virtualizing-vcenter-with-vds-catch-22/ [...]

By: VM’s can’t ping while on Distributed Virtual Switches VLAN’s « TheSaffaGeek

Mon, 08 Mar 2010 13:01:32 +0000

[...] http://www.boche.net/blog/index.php/2009/10/09/virtualizing-vcenter-with-vds-catch-22/ [...]

By: Design Challenges Of Virtualized vCenter With A vNetwork Distributed Switch | VM /ETC

Mon, 08 Mar 2010 02:41:57 +0000

By: vSphere 4 Update 1 Released | Expert Data Labs Blog

vSphere 4 Update 1 Released | Expert Data Labs Blog — Fri, 20 Nov 2009 17:01:17 +0000

[...] October 9, 2009 — Virtualizing vCenter With vDS Catch-22 [...]

By: Linus T.

Linus T. — Thu, 29 Oct 2009 18:07:35 +0000

Jason, the solution to this is to turn the port group from the default Static binding to Ephemeral. You’ll then be able to access it when connecting directly to the ESX host and thus, assign your vCenter to it.

Remember, however, that you need to change the binding BEFORE adding VMs to it (so creating 3 port groups, one of each binding, would help in this scenario)

By: Andy Daniel

Andy Daniel — Mon, 26 Oct 2009 17:51:13 +0000

For this reason and others, I’m recommending most customers use the “Hybrid” approach to vDS, or at least keep a backup SC on a classic standard vSwitch.

Just ran across this note regarding the Nexus 1kv VEM install…

“VUM will not install the VEM software on a host where the vCenter resides. The vCenter must be migrated to another host before installing VEM software.”

I’m assumming that this is to avoid a similar situation to that which you describe. I’m planning on migrating vCenter, installing the VEM and migrating back.

By: Massimo Re Ferre'

Massimo Re Ferre' — Wed, 14 Oct 2009 09:00:58 +0000

Jason,

FYI I sort of experienced a similar catch22 when I tried (in the lab) to modify the EVC configuration of my 2 hosts cluster (vCenter was running as a VM on top of it). Off the top of my mind.. the problem was that, in order to change the EVC policy all VMs on the cluster were to be off…. but since the change of the policy is only available within VC.. and VC was running on the cluster…… catch22….

Massimo.

By: Tom Howarth

Tom Howarth — Wed, 14 Oct 2009 08:36:19 +0000

gogogo5:- I believe that the issue only relates to Hosts running Nexus 1000v switches, not basic vNDS switches. Here the data plane is shared across all hosts and highly available.

Thanks to Rob as that is a Design issue I did not know about.

To me the biggest issues regarding Virtual Infrastructure is the inability to start a server hosting a license server, this is very much the chicken and egg scenirio and some thing VMware need to get addressed.

One thing I do not have access to a lab at the moment but how is licensing affected in pure vSphere environments?

By: gogogo5

gogogo5 — Wed, 14 Oct 2009 01:17:11 +0000

Calling all vExperts, lots of good questions needing your attention

By: gogogo5

gogogo5 — Tue, 13 Oct 2009 00:23:55 +0000

Things can get even stickier if you have enabled Lockdown mode (and still rely on using root as your VIC login) and then your vCentre server goes down. Can you then point your vSphere client to your ESX(i) host that has been configured for Lockdown mode…hhmmmm…..

Can you disable Lockdown Mode via the console on a per host basis to override this?

Can someone validate Iben’s assessment above, is his theory correct i.e.:

vCenter is on dvs
ESX vCenter is on dies
vCenter vm starts up on new ESX since it’s protected with HA
VCenter won’t have network since dvs cannot be reconfigured on new ESX

Is this correct?

By: iben rodriguez

iben rodriguez — Sun, 11 Oct 2009 19:04:25 +0000

Okay, I’m starting to get the problem(s) here…

vCenter is on dvs
ESX vCenter is on dies
vCenter vm starts up on new ESX since it’s protected with HA
VCenter won’t have network since dvs cannot be reconfigured on new ESX

Is this correct?

If it is then it seems like vCenter should have non-dvs portgroup to manage ESX hosts.

By: Rob

Rob — Sun, 11 Oct 2009 18:00:35 +0000

Iben, I believe HA will work but the restarted VM will not have a network connection until vCenter has reconfigured the VEM on the host. obviously if the restarted VM is the vCenter server and its network is on a DVS it will not be able to reconfigure it.
i may be wrong here but this is definitely the case with DRS / vMotion – if vCenter is not available or not properly connected to the VSM the VM will still move but will lose it’s network connection.

By: jason

jason — Sun, 11 Oct 2009 04:17:34 +0000

A Linked vCenter would not have solved the problem.

By: Andre Leibovici

Andre Leibovici — Sun, 11 Oct 2009 04:11:08 +0000

It seems to me that this problem would have been avoided if you had a Linked VCenter instance. Is that right?