Streched Cluster with Witness network

[COM6fafa]

Hie

I would want to set up a strech cluster with 8 hosts distributed on 2 sites and 1 host witness on the third site.

What is that even for a strech cluster, we can separate the vSAN network and Witness network, or it is only to reserve in a typical infrastructure ROBO with 2 nodes

[TheBobkin]

Hello COM6fafa,

WTS (Witness Traffic Separation) is only intended for 2-node clusters:

https://blogs.vmware.com/virtualblocks/2016/10/18/2nodedirectconnect/

http://www.yellow-bricks.com/2016/10/18/new-virtual-san-6-5/

https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.virtualsan.doc/GUID-03204C22-C069-4...

Hope this helps.

Bob

[COM6fafa]

Hello TheBobkin

No I understood well that TWS was useful for an infrastructure ROBO; but can also one use him(it) in an infrastructure Streched Cluster. To use the VSAN network with a MTU 9000 and the network witness with a MTU on 1500.

[TheBobkin]

Hello COM6fafa​

WTS *can* be configured on any type of Stretched-cluster - whether there is any benefit to doing so depends on the set-up.

Whether it is officially supported outside of ROBO/2-node direct-connect is hard to find information on but I cannot find anywhere that explicitly states that it is not supported and cannot think of any reason why it might cause issues.

Bob

[TheBobkin · Accepted solution]

Scratch that - appears to be an unsupported configuration and probably for a reason:

"Witness Traffic Separation is not supported on Stretched Cluster configurations."

https://storagehub.vmware.com/#!/vmware-vsan/vsan-stretched-cluster-2-node-guide/witness-traffic-sep...

Bob

[COM6fafa]

Bob thank you for this information that is not very available which is very important