In addition to Dan's reply, operating systems ought to indicate what stage they have reached in the boot process (eg. "BIOS up", "kernel up", "userspace up", "applications started"), perhaps by writing a status code into a register. Some PC BIOSes do this already, writing to IO port 0x80, see for example: http://lkml.indiana.edu/hypermail/linux/kernel/0203.1/0770.html If you are using a watchdog driver, feasibly you might use this to detect when userspace in the guest is active. Anyway, this is worth discussing with the relevant upstream projects, QEMU, IPMI, various watchdog hardware ... Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://et.redhat.com/~rjones/libguestfs/ See what it can do: http://et.redhat.com/~rjones/libguestfs/recipes.html -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list