VCHA "appliance configuration is out of sync" and state: degraded after failover

Products

• VMware vCenter Server

Issue/Introduction

• After VCHA failover, entered a degraded state with the alert “appliance configuration is out of sync"
  
  
• /var/log/vmware/vcha/vcha.log shows connection error similar with
  
  yyyy-mm-ddThh:mm:ss.xxx+xx:xx error vcha[xxxxx] [Originator@xxxx sub=RsyncRepl-smallFrp] Rsync failed, retcode: 12, error: ssh: connect to host xxxx:<IP address of secondary VC IP> port 22: Connection refused
  --> rsync: connection unexpectedly closed (0 bytes received so far) [sender]
  --> rsync error: error in rsync protocol data stream (code 12) at io.c(232) [sender=3.4.1]
  
  

Environment

vCenter Server 8.x

Cause

SSH is require for initial deployment of VCHA, so it must enable when enable VCHA.

When disable SSH after the initial sync occurs at enabling VCHA, cluster become out of sync if any subsequent VCHA failovers occur.

Resolution

Enable SSH on all Primary, Secondary and Witness nodes.

Additional Information

How to enable SSH service on vCenter Server Appliance