After being asked about how vSphere Host Groups worked with Availability Zones in Enterprise PKS earlier this week, I decided to spend a little time setting it up in my lab and doing some testing to make sure I could understand the feature and its behaviour. Essentially what this feature allows you to do is to make use of the vSphere Host Group feature to group a bunch of ESXi hosts together. Then as one builds Availability Zones (commonly referred to AZs) in Enterprise PKS, a Host Group can be associated with an AZ. Anything that Enterprise PKS deploys to…
I was looking into some behavior recently to assist one of our partners. He described a situation that they observed during proof-of-concept testing. I thought it would be of benefit to highlight this behavior in case you also observe it, and you are curious as to why it is happening. Let’s begin with a description of the test. The customer has a 7-node vSAN, and has implemented RAID-6 erasure coding for all VMs across the board. The customer isolated one host, and as expected, the VMs continued to run without issue. The customer was also able to clones virtual machine…
One of the really nice new features of VSAN 6.0 is fault domains. Previously, there was very little control over where VSAN placed virtual machine components. In order to protect against something like a rack failure, you may have had to use a very high NumberOfFailuresToTolerate value, resulting in multiple copies of the VM data dispersed around the cluster. With VSAN 6.0, this is no longer a concern as hosts participating in the VSAN Cluster can be placed in different failure domains. This means that component placement will take place across failure domains and not just across hosts. Let’s look…