Re: [Qemu-devel] Hardware watchdogs (patch for discussion only)

["Richard W.M. Jones" <rjones@redhat.com>]

On Thu, Feb 26, 2009 at 02:31:22PM +0000, Steve Fosdick wrote:
> On Thu, 2009-02-26 at 10:51 +0000, Daniel P. Berrange wrote:
> 
> > I think we can only support the following options
> > 
> >  - shutdown - graceful shutdown of guest via ACPI event via
> >               qemu_system_powerdown_request()
> 
> I wonder how many times the guest will be healthy enough to respond to
> this and how many times it will have crashed badly enough that this does
> no good.
[...]
> Do we want to offer the guest the option of a clean shutdown if it can
> still manage that and then reboot, i.e. the shutdown option but for use
> case 1?

The Intel 6300ESB in fact offers this possibility already.  As with
other high-end watchdog hardware, it can be configured to send a
"pretimer interrupt".  For example, if the watchdog is set to expire
after 60 seconds, you can get an interrupt N seconds before this,
which you can use to try a graceful shutdown.

Having said that, Linux watchdog software doesn't support this feature ...

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/