What more do I need to say? vSphere 6.0 U1 was released today and it ships with Virtual SAN 6.1. By now you’ve all seen my posts on what’s new for VSAN 6.1 and you’ve hopefully seen the demo we created for stretched clustering. If you want to play with 6.1 yourself then you can find it here:
I posted about HA/DRS settings for VSAN Stretched Clustering yesterday and posted an intro to 6.1 and all new functionality which includes stretched clustering. As part of our VMworld session Rawlinson Rivera recorded a nice demo. We figured we should share it with the world, so I added the voice-over so at least it is clear what you are looking at and why certain things are configured in a specific way. I hope this demo shows how dead simple it is to configure VSAN stretched clustering, and how it handles a full site failure. Enjoy,
This question is going to come sooner or later, how do I configure HA/DRS when I am running a Virtual SAN Stretched cluster configuration. I described some of the basics of Virtual SAN stretched clustering in a what’s new for 6.1 post already, if you haven’t read it then I urge you to do so first. There are a couple of key things to know, first of all the latency between data sites that can be tolerated is 5ms and to the witness location ~100ms.
If you look at the picture you below you can imagine that when a VM sits in Fault Domain A and is reading from Fault Domain B that it could incur a latency of 5ms for each read IO. From a performance perspective we would like to avoid this 5ms latency, so for stretched clusters we introduce the concept of read locality. We don’t have this in a non-stretched environment, as there the latency is microseconds and not miliseconds. Now this “read locality” is something we need to take in to consideration when we configure HA and DRS.