I have run into a scenario after installing the client agent.  If a VM is shutdown, the client agent calls the shutdown command with a 1 minute timeout.

Dummy-2::INFO::2013-03-28 14:05:21,892::vdsAgentLogic::138::root::Shutting down (timeout = 30, message = 'System Administrator has initiated shutdown of this Virtual Machine. Virtual Machine is shutting down.'

Since the shutdown command is called with time parameter the VM sets the /etc/nologin file. When the VM is forced down the /etc/nologin file is not cleared and when it comes back up only root can login until the /etc/nologin file is cleared.

Is their some some reason the shutdown time is set to 30 seconds (rounded up to 1 minute in the code)?  Are there any know issues with setting this to 0?

Is this the right way to change it to 0?

psql engine postgres -c "update vdc_options set option_value = '0' where option_name = 'VmGracefulShutdownTimeout';"