BitFolk » Panel

Xen has a watchdog feature. Inside a guest, if the xen_wdt module is loaded then this will tell the hypervisor to raise a watchdog expired event if the guest does not check in regularly.

The default action the hypervisor takes when receiving a "watchdog expired" event is to destroy the guest.

For this feature to be useful, many people would instead wish for their virtual machine to be restarted, which is an available action for this event.

A select box of events should be added to the "prefs" section of the panel. It need only contain "destroy" and "restart" at the moment; there doesn't need to be a "none" option because the Xen watchdog is only enabled when xen_wdt is loaded inside the guest kernel. It is not typically loaded by default.

Although the default action is "destroy", it might make more sense for us to set the default action to be "restart". "destroy" is something that people building clusters typically want, to ensure that a fenced node really is offline (STONITH). But I expect that the majority of BitFolk customers would instead prefer their VPSes to reboot, therefore perhaps we should default to "restart".

Is there anyone at BitFolk using xen_wdt in the "destroy" mode?