Which vSAN Maintenance Mode option was used on a host?

Last week there was a question on VMTN around maintenance mode, this customer wanted to find out which vSAN Maintenance Mode option was used while the host was placed in maintenance mode. The person who placed the host into maintenance wasn’t around, and I guess the customer wanted to know if data was moved from … [Read more...]

HCI Mesh error: Failed to run the remote datastore mount pre-checks

I had two comments on my HCI Mesh compute only blogpost where both were reporting the same error when trying to mount a remote datastore. The error that popped up was the following: I tried to reproduce it in my lab, as both had upgraded from 7.0 to U2 I did the same, that didn’t result in the same error though. … [Read more...]

Does vSAN Enhanced Durability work when you have a limited number of hosts?

Last week I had a question about how vSAN Enhanced Durability works when you have a limited number of hosts. In this case, the customer had a 3+3+1 stretched cluster configuration, and they wondered what would happen when they would place a host into maintenance mode. Although I was pretty sure I knew what would … [Read more...]

Using HCI Mesh with a stand-alone vSphere host?

Last week at the French VMUG we received a great question. The question was whether you can use HCI Mesh (datastore sharing) with a stand-alone vSphere Host. The answer is simple, no you cannot. VMware does not support enabling vSAN, and HCI Mesh, on a single stand-alone host. However, if you still want to mount a vSAN … [Read more...]

Can I vMotion a VM while IO Insight is tracing it?

Today during the Polish VMUG we had a great question, basically, the question was if you can vMotion a VM while vSAN IO Insight is tracing it. I did not know the answer as I had never tried it, so I had to test and validate it in the lab. While testing it became obvious that IO Insight and vMotion are not a supported … [Read more...]

What if the disk controller driver included in my vendor’s ESXi image is not on the vSAN HCL?

Sometimes unfortunately there are situations where a vendor’s ESXi image includes a disk controller driver that is not on the vSAN HCL/VCG (VMware Compatibility Guide). Typically it is a new version of the driver which is supported for vSphere, but not yet for vSAN. In that situation, what should you do? So far … [Read more...]

VMs which are not stretched in a stretched cluster, which policy to use?

I’ve seen this question popping up regularly. Which policy setting (“site disaster tolerance” and “failures to tolerate”) should I use when I do not want to stretch my VMs? Well, that is actually pretty straight forward, in my opinion, you really only have two options you should ever use: … [Read more...]

vSphere HA reporting not enough failover resources fault with stretched cluster failure scenario

Last few months I had a couple of customers asking why vSphere HA was reporting “not enough failover resources” fault in a stretched cluster failure scenario for virtual machines that are still up and running. Now before I explain why, let’s paint a picture first to make it clear what is happening … [Read more...]

How to login to the vCLS VMs!?

I was asked this question this week, how you can login to the vCLS VMs. Now before I share the video, I want to mention that I do not encourage people doing this, but as it is documented and supported I do want to provide a simple “how to” for how this works. If you want to login to the vCLS VM, maybe for … [Read more...]

Which vSAN policy changes will trigger a rebuild?

A couple of years ago I did a VMworld session with Cormac and we discussed the top things everyone should know about vSAN. One of the items discussed was which policy changes would trigger a rebuild. We tested the various situations and documented them. Two weeks ago a question around this was asked on a VMware … [Read more...]