Using alternate ESXi command line methods to power off the virtual machine
1. On the ESXi console, enter Tech Support mode and log in as root. For more information, see Tech Support mode for Emergency Support (1003677).
2. To list all running virtual machines and their corresponding VMIDs, run the command:
vim-cmd vmsvc/getallvms
3. Power off the virtual machine using the VMID found in Step 2 and run:
vim-cmd vmsvc/power.off <vm id> for ESXi 3.5 and 4.0
vim-cmd vmsvc/power.off <vmid> for ESXi 4.1
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1014165
