[ovirt-users] where to get information about wdmd, sanlock logic

Hello, is wdmd similar to the old watchdog daemon that was used to kill node (eg in old Oracle 9i RAC environments on Linux)? Is it stoppable at all without having host reboot itself? I see many other daemons on the hypervisor but not so clear the correlation between them and inter-dependency Eg momd, vdsmd, supervdsmd or ovirt-ha-agent, ovirt-habroker Suppose I have an environment with only one host up (eg single host environment but not only; think about a site where due to planned maintenance I have to stop all one at a time), do I have a way to put the host in single user mode without having it automatically reboot itself? Any docs? Thanks, Gianluca