Hi, Am 18.01.2016 um 12:43 schrieb lejeczek: > I'm trying Qemu's watchdog. > My understanding was that hardware (here qemu's watchdog) would take > action, eg. cold reboot the system if there is no ping from the OS > watchdog, so I > thought stopping watchdog service in VM should be a quick test, right? > > I have this in the guest: > > <watchdog model='i6300esb' action='reset'> > <address type='pci' domain='0x0000' bus='0x00' slot='0x08' > function='0x0'/> > </watchdog> > > and I see /dev/watchdog in my guest. Yet nothing happens, guest(linux) > runs uninterrupted. > I must be missing something, an expert said it's config problem, is it > really is?
Probably reading linux/Documentation/watchdog/watchdog-api.txt should give you some extra hints. AFAIK you need to open that device file at least once, either with the sample program included in the Linux source tree, or by another program like (Debian) watchdog or systemd (man 5 systemd-system.conf -> RuntimeWatchdogSec) cat /dev/watchdog # will print an error about the read(), but the important thing (opening the file) has been done dmesg | grep watchdog # will print "i6300esb: Unexpected close, not stopping watchdog!" to show you that the watchdog is still running and will trigger the reboot, as it has gone through the shutdown protocol, which can be used to disable the watchdog again After ~1m my test VM rebooted. Philipp
