You are unable to configure HA on a cluster as vCenter is unable to get the base image spec for the cluster

Products

• VMware vCenter Server

Issue/Introduction

• Error: "vCenter Server is unable to find a master vSphere HA agent in cluster <cluster_name>"
• The cluster uses vLCM image
• The vmware-updatemgr service on the vCenter is in a STOPPED state
• The vpxd log shows that vCenter is unable to determine the base image:

2026-02-16T<time>Z info vpxd[94224] [Originator@6876 sub=DAS opID=mlhraif2-241487-auto-56c0-h5:70033603-3a-01] Getting base image spec for cluster domain-c####

2026-02-16T<time>Z warning vpxd[94343] [Originator@6876 sub=HttpConnectionPool-000001 opID=mlhraif2-241487-auto-56c0-h5:70033603-3a-01] Failed to get pooled connection; <cs p:00007f6dec1ed270, TCP:localhost:8083>, (null), duration: 0msec, N7Vmacore15SystemExceptionE(Connection refused: The remote service is not running, OR is overloaded, OR a firewall is rejecting connections.) --> [context]zKq7AVECAQAAALa6fwEMdnB4ZAAAyzdIbGlidm1hY29yZS5zbwAArDA3AA9VOAAggi0AfaItAFGzLQDrwS0ABPwsAA9VLQDrKkYBxJAIbGliYy5zby42AAGskRA=[/context]

2026-02-16T<time>Z error vpxd[94224] [Originator@6876 sub=DAS opID=mlhraif2-241487-auto-56c0-h5:70033603-3a-01] Couldn't get Base Image for Cluster: domain-#### 2026-02-16T<time>Z info vpxd[94224] [Originator@6876 sub=MoHost opID=mlhraif2-241487-auto-56c0-h5:70033603-3a-01] VC state for host host-1001 (uninitialized -> retry), FDM state (UNKNOWN_FDM_HSTATE -> UNKNOWN_FDM_HSTATE), src of state (null -> null)

• It is clear that vCenter cannot establish a connection over port 8083 as the underlying service (vmware-updatemgr) is not available
• Port 8083 is a required port for vLCM access to ESXi.

Environment

vCenter 9.x

Cause

• HA cannot be configured while the vmware-updatemgr service is unavailable. 
• This service is responsible for managing the base images that vSphere HA now leverages for cluster consistency.

Resolution

• Start the vmware-updatemgr service:

service-control --start vmware-updatemgr service

• Reconfigure HA for the cluster