In order to reproduce, get a VC/PSC 6.7 . Make the /storage/log full 100% . Installation fails with unexpected problem.
Step two, you clean up the /storage/log a bit and it still fails.
After this i made sure that there is 98% free. And same error occurs.
You can reboot PSC/VC as many times as you want, that does not help. In order to fix it, login to your VC/PSC box and delete file:
/etc/applmgmt/appliance/software_update_state.conf
After file is gone, or moved , go back to installer and click update -> it works !
Have a look what was causing the error :
And the installer script was looking at it hence failing while spotting INSTAL_FAILED with this cryptic error message that the vcenter is not operational
/usr/lib/applmgmt/update/py/vmware/appliance/update/update_state.py
Many thanks to Ciaran from @VMware for spotting that!