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 Datastore from a single vSphere host, there is a way around this limitation.
First, let’s list the requirements:
- The host needs to be managed by the same vCenter Server as the vSAN Cluster
- The host needs to be under the same virtual datacenter as the vSAN Cluster
- Low latency, high bandwidth connection between the host and the vSAN Cluster
If you meet these requirements, then what you can do to mount the vSAN Datastore to a single host is the following:
- Create a cluster without any services enabled
- Add the stand-alone host to the cluster
- Enable vSAN, select “vSAN HCI Mesh Compute Cluster”
- Mount the datastore
Note, when you create a cluster and add a host, vCenter/EAM will try to provision the vCLS VM. Of course this VM is not really needed as HA and DRS are not useful with a single host cluster. So what you can do is enable “retreat mode”. For those who don’t know how to do this, or those who want to know more about vCLS, read this article.
As I had to test the above in my lab, I also created a short video demonstrating the workflow, watch it below.
Andrea Scarabelli says
Hi Duncan, as I can read this seems to be a legit workaround just because formally (and in the end, technically) vSAN activation procedure needs a Cluster.
But is this path officially supported? I mean: I am allowed to have in production a cluster with a single node leveraging storage resource from another cluster using vSAN HCI Mesh?
Duncan Epping says
Yes, this is officially supported according to the vSAN Product Managers.