Earlier today Virtual IEF posted a blog about not being able to access an ESX host, not by ssh, not by VIC and not even through vCenter. Evidently this is caused by the hardware monitoring agents (HP, Dell, etc) auto-detecting the management server and failing authentication. This causes cimservera to be spawned hundreds if not thousands of times thus causing so much CPU and Network traffic locally that it cannot respond within the thresholds for SSH, or VPX agents.
Unable to login through SSH to VMware ESX host
Unable to login on local Service console
root 6377 0.0 0.0 0 0 ? Z Sep24 0:00 [cimservera
root 6496 0.0 0.0 0 0 ? Z Sep24 0:00 [cimservera
Nov 17 18:29:34 blr-cpd-018 cimservera: user “root” failed to authenticate
Nov 17 18:29:36 blr-cpd-018 cimservera: user “root” failed to authenticate
Nov 17 18:29:39 blr-cpd-018 cimservera: user “root” failed to authenticate