Distributed vSwitch working without vCenter?

[Svedja]

We are looking at migrating from standard vSwitch to Distributed vSwitch in the near future but I need to asses possible headaches regarding that.

Distributed vSwitch requires vCenter according to various documents.

1. Does that mean it is required that it is needed for configuration only or will it stop working ie. if the vCenter would be unreachable/crashed?

2. If I would be forced to reinstall vCenter, what happends to the Distributed vSwitches?

3. If we would migrate the ESX-servers to another vCenter, would the ESX configuration work?

When we upgraded from ESX3.5 to ESX4.0 we simply disconnected the ESX servers from the old vCenter2.5 and connected to the new vCenter4 without any network related problems and could do it without any disruption for the running virtual machines.

With Distributed vSwitch and vCenter requirement it is not clear from the documents if we could do such an operation in the future.

Does anyone have answers for the questions? Anyone tried?

[depping]

1) Only needed for configuration, if vCenter fails the dvSwitch will still work.

2) If vCenter needs to be reinstalled you will need to reinstall the dvSwitch as well, maybe try to create them via a script or make sure you back the database

3) There is a document on migrating hosts into a vDS environment: http://vmware.com/files/pdf/vsphere-vnetwork-ds-migration-configuration-wp.pdf

Duncan

VMware Communities User Moderator | VCDX

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[kjb007 · Accepted solution]

A distributed vSwitch will use "hidden or proxy" vswitches to perform tasks on the host itself.

So, the vCenter is required only for configuration, and a host will

continue functioning if the connection is lost.

That being said, the config is part of the vCenter, so you will have problems if you have to migrate or rebuild vCenter. Here's a previous post that describes some problems, and a workaround: http://communities.vmware.com/message/1400976#1400976

-KjB

[Svedja]

Thank you both for a helpfull answer.

[firestartah]

Hi

Having done the migration myself it is a very carefully planned maneuver but it is possible without disrupting your vm's. The best way i found and used was to add the hosts to the distributed virtual switch and either configure one nic (assuming you have more than one) for the distributed virtual switch and leave the other on the standard virtual switch. Then use the tool in the distributed vswitch summary page (can't remember the exact wording as have changed my environment now) to convert all the machines from the old switch port groups to the new distributed vSwitch port groups. This way there should be no downtime as the hosts will have a nic (or two if you have 4 nic's setup) configured for each side. Then once all migrated either go through the add hosts wizard again and add the second nic from the older standard vSwitch or if you used two spare nic ports you can either configure these from dedicated VMotion ports or remove them.

I wrote blog posting on some of the problems i came across with distributed vswitches http://thesaffageek.wordpress.com/2010/03/08/vms-cant-ping-while-on-distributed-virtual-switches-vla...

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Gregg Robertson, VCP3,4 , MCSE, MCSA, MCTS, MCITP