How do I tell ESXi 5.5 to autostart virtual machines from ssh/CLI only?

Solution 1:

Instead of tinkering with the config file you should use the vim-cmd command (and its namespace hostsvc/autostartmanager) to configure VM autostart. Run

vim-cmd help hostsvc/autostartmanager

to get help. A good overview with examples is here: http://msmhec.pl/vmw/Documents/VIM-CMD.pdf (mentions ESXi 4.1, but still applies to recent ESXi versions)