Rebooting ESX/ESXi when Storage vMotion is in progress might create a duplicate virtual machine with the same name (1023182)
Rebooting the ESX/ESXi host when Storage vMotion is in progress (approximately 50% complete) might result in vSphere Client displaying two virtual machines with the same name and configuration. However, only one of the virtual machines boots properly.
Though an aspect of this issue is resolved in vSphere 4.0 U2, be aware that you might still see two virtual machines. Now, ESX/ESXi prevents you from powering on the wrong virtual machine and issues an error message indicating that you should power on the other virtual machine.