Here’s the error

While building a new environment for my lab, I ran across an interesting thing yesterday.

I looked at my cluster’s VSAN health and saw this error:

It’s complaining that my hosts don’t have matching Virtual SAN advanced configuration items.

If you click on that error, you’ll see at the bottom where it shows comparisons of hosts and the advanced configurations:

It shows VSAN.DomMaxLeafAssocsPerHost and VSAN.DomOwnerInflightOps as being different between a few of my hosts. Looking at the image above, you’ll see node 09 has values of 36000 and 1024, respectively, while the other nodes 10-12 show 12000 and 0.

I immediately went to the host configuration advanced settings in the web client, searched VSAN and don’t see either of those. I even checked through PowerCLI and can’t see those:

If I look directly for the specific configuration item, I can see it, though:

However, you cannot change these items, that’s why they don’t show up when you look in the GUI or search via PowerCLI. I actually tried, which is how I know you can’t :P

What’s the problem?

The reason these hosts show up differently is because I just recently built node 09 with ESXi 6.0U1 after I had already built the other nodes as 6.0. ESXi 6.U1 allows more total objects in VSAN per host (VSAN.DomMaxLeafAssocsPerHost), as well as increased concurrent file operations (VSAN.DomOwnerInflightOps).

How do I fix it?

In the event you see this error, you’ll want to upgrade your ESXi hosts with the older build number, despite both being 6.0, to ensure you’re on the same update and VSAN version.

I used VUM to upgrade all the other hosts to 6.0U1 and those messages went away. Just wanted to share!