This article provides the steps to be followed when renewing CA certificate on vCenter.
In case the custom SSL certificate is already expired ,any of the following errors/issues may be observed while accessing the vCenter UI:
HTTP Status 500 – Internal Server ErrorNo healthy upstreamAfter the certificate replacement has been attempted in a case where it has not yet expired, if the process to take the vCenter snapshot was performed while vCenter HA is still active, vCenter will appear to be in a down state after a reboot, and the IP address assigned to the eth0 interface will not respond to pings.
vCenter 7.x
vCenter 8.x
Ensure you take a powered-off snapshot of the vCenter Server for backup:
If the vCenter is using vCenter High Availability (VCHA), you must destroy the VCHA configuration before taking the snapshot.
vcha-destroy -f
Caution: Do not take snapshots while vCenter HA is enabled. Before Enabling vCenter HA you must first Delete All snapshots.
Renew the expired certs using vCert tool:
vCert script from KB vCert - Scripted vCenter Expired Certificate Replacement.service-control --stop --all && service-control --start --all
Note: If other certificates are still expired then all services may not start yet even though you have replaced the expired CA certificate.
Verify an expired CA certificate is not in use
/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store TRUSTED_ROOTS --text
/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store MACHINE_SSL_CERT --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store machine --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store vpxd --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store vpxd-extension --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store vsphere-webclient --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store SMS --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store hvc --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store data-encipherment --text | more/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store wcp --text | more
/usr/lib/vmware-vmafd/bin/vecs-cli entry list --store TRUSTED_ROOT_CRLS --text | more

Remove a vCenter HA Configuration