VM Power-on Failure: 'No host is compatible with the virtual machine'

Products

• VMware vCenter Server
• VMware vSphere ESXi 8.0

Issue/Introduction

• Virtual machine power-on task fails immediately with the error "No host is compatible with the virtual machine"

• Validation of the ESXi host where the affected VM is registered shows a HA configuration issue with message: "Unable to configure HA agent on host, task fails with error 'There was an error unconfiguring the vSphere HA agent on this host".

• DNS resolution of vCenter Server FQDN using 'nslookup' fails with error "connection timed out; no servers could be reached.

Cause

• The ESXi host failed to resolve itself and vCenter Server's FQDN (Fully Qualified Domain Name) via its A Record and PTR Record, preventing communication with vCenter Server affecting Host's vSphere HA.
• As the vSphere HA failed to configure on the host, the DRS evaluated the host's health score as poor and was unable to identify a compatible host to power on the virtual machine.

Resolution

• Ensure DNS server is reachable to the ESXi host and can resolve the vCenter FQDN.

• • Connect to ESXi host SSH.
    
    
  • Use the nslookup command to verify that the ESXi host can resolve vCenter Server, other ESXi hosts in the cluster and itself.
    
    

cat /etc/resolv.conf

Nameserver : # DNS server IP

Domain name: example.com

• • Get DNS IP

• • Run the command to validate the DNS response 'nslookup <hostname> <dns_server_IP>' 

Example:[root@esx-server-1 ~]# nslookup <hostname> <dns_server_IP>
Server:         192.##.##.##   # DNS server IP
Address:        192.##.##.##

Name:           esx_hostname.example.com
Address:        192.##.##.##   # Expected IP address of esx_hostname

• • If the DNS resolution fails, the forward lookup is failing.
    
    
  • Ensure that the DNS server contains an A record for the affected ESXi host or vCenter, in both forward and reverse lookup DNS.
    
    
  • If DNS server is not reachable to the ESXi host, ensure the DNS server is reachable to the ESXi host with A Record in forward and reverse lookup DNS.