This will be a very quick KB article style blog post.

Symptoms

• You see a banner that reads Could not connect to one or more vCenter Server systems: <VC FQDN>:443/sdk when logging into linked-mode vCenter
• You may be missing one or more vCenters from the inventory tree, depending on which vCenter you log into

Possible Causes

• vCenter services failing
• Disk space low
• Network/firewall blocking communication
• Platform Services Controller misconfiguration: VMware KB 2050273

You can check on VAMI (:5480) to verify health of services, database, and disk space.

Diagnosis

Here are some commands you can run to see what vCenter is doing behind the scenes!

• /usr/lib/vmware-vmdir/bin/vdcrepadmin -f showpartnerstatus -h localhost -u administrator
• /usr/lib/vmware-vmdir/bin/vdcadmintool » option 6
• Check in VPXD logs
• Check ping/telnet
• More documentation here: VMware KB 2127057