Witness in L2 or L3

[jbednarz]

Hello,

I want to start the high availability service for vCenter (6.7) and in this case there must be a witness. I found something like this :

• vCenter HA network latency between Active, Passive, and Witness nodes must be less than 10 ms.
• The vCenter HA network must be on a different subnet than the management network.

And now I have a few questions:

1. The witness must be on the same subnet as the active and passive node?

2. If it doesn't have to be how much better it is in the same subnet or another?

3. What will happen if the latency is not guaranteed between all nodes?

4. What if the witness cannot be reached?

Thanks for the help

[dbalcaraz]

Hi,

1. The witness must be on the same subnet as the active and passive node?
Yes because they have to communicate in order to sync. Check this article: vCenter HA Deployment Options

2. If it doesn't have to be how much better it is in the same subnet or another? Check the previous article.

You need a subnet for the nodes (an internal subnet) and then an additional interface for the active node.

3. What will happen if the latency is not guaranteed between all nodes? Failures can occur and they won't be on sync.

4. What if the witness cannot be reached? The VCHA could be broken if there is a lot of time since they have been on sync.

Hope this helps.