[CentOS-virt] reboot guest on panic

Sun Mar 14 22:42:34 UTC 2010
Norman Gaywood <ngaywood at une.edu.au>

Thanks Dan,

On Sun, Mar 14, 2010 at 05:06:32PM -0400, Dan Hrabarchuk wrote:
> Try this in the guest:
> 
> echo "1" > /proc/sys/kernel/panic_on_oops

This might be a bit too much. There is another "harmless" oops that occasionally
happens related to ext4 quotas. I wouldn't want it to reboot on those.

The hung_task_panic=1 does in fact cause the panic when I want it.
However the problem seems to be that it does not reboot after the panic.

> echo "5" > /proc/sys/kernel/panic

I already have this, although I have a value of 15.

 
> On 03/13/2010 05:03 PM, Norman Gaywood wrote:
> > I have a guest that keeps crashing and want to automatically reboot it
> > when it crashes. See:
> >
> >    xen PV guest kernel 2.6.32 processes lock up in D state
> >    https://bugzilla.redhat.com/show_bug.cgi?id=550724
> >
> > if you want to look at the details on the crashing.
> >
> > Anyway, I boot the guest with the kernel command line parameter:
> >
> >    hung_task_panic=1
> >
> > I have kernel.panic = 15 in the guest /etc/sysctl.conf
> >
> > In the guest config file in dom0 I have:
> >
> >    on_poweroff = "destroy"
> >    on_reboot = "restart"
> >    on_crash = "restart"
> >
> > The guest manages to panic when it detects the hung tasks and I get this
> > on the guest console:
> >
> >    Kernel panic - not syncing: hung_task: blocked tasks
> >    Rebooting in 15 seconds..
> >
> > However, it never restarts. It just hangs around until I do a
> >
> >    xm destroy<guest>
> >    xm create<guest>
> >
> > Have I missed something?

-- 
Norman Gaywood, Computer Systems Officer
University of New England, Armidale, NSW 2351, Australia

ngaywood at une.edu.au            Phone: +61 (0)2 6773 3337
http://mcs.une.edu.au/~norm    Fax:   +61 (0)2 6773 3312

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