vSAN Health Service - Preferred fault domain unset

Products

• VMware vSAN

Issue/Introduction

The Preferred fault domain unset check in the vSAN Health Service verifies that the preferred fault domain is configured, and that it is the fault domain of one of the two data sites in the stretched cluster.

The preferred fault domain is utilized by the witness host, and it must be the fault domain of either data site in the vSAN stretched cluster. It cannot be empty. If this health check is not green (OK), the vSAN stretched cluster has configuration errors that affect its operation and may cause unexpected results in failover scenarios.

Environment

VMware vSAN 6.2.x
VMware vSAN 7.0.x
VMware vSAN 6.x
VMware vSAN 6.0.x
VMware vSAN 6.1.x
VMware vSAN 8.0.x

Resolution

To troubleshoot or resolve this issue, configure the preferred fault domain.

To configure the preferred fault domain:

1. Run the esxcli vsan cluster preferredfaultdomain get command:

2. Set the preferred fault domain:

Note: You can run the command on any host to view the preferred fault domain. To set the preferred fault domain, you must run the command on the witness host.

Additional Information

You can collect information about the preferred fault domain by querying CMMDS from a host.

For example:

[root@:~] cmmds-tool find -t PREFERRED_FAULT_DOMAIN

owner=558c3ca0-e92f-c784-8b00-020001ff8d0e(Health: Healthy) uuid=558c3ca0-e92f-c784-8b00-020001ff8d0e type=PREFERRED_FAULT_DOMAIN rev=0 minHostVer=0 [content = (f198f054-98f8-01a3-916c-2a0bc4907bb5 "fd1")], errorStr=(null)