Re: one out of four existing kvm guest's not starting after system upgrade

[Thomas Fjellstrom <thomas@fjellstrom.ca>]

On Sat Feb 18, 2012, Thomas Fjellstrom wrote:
> On Sat Feb 18, 2012, Jan Kiszka wrote:
> > On 2012-02-18 05:49, Thomas Fjellstrom wrote:
> > > I just updated my kvm host, kernel upgraded from 2.6.38 up to 3.2, and
> > > qemu+qemu-kvm updated (not sure from what to what). But after the
> > > upgrade, one of my guests will not start up. It gets stuck with 60-80%
> > > cpu use, almost no memory is allocated by qemu/kvm, and no output of
> > > any kind is seen (in the host console, or a bunch of the guest output
> > > options like curses display, stdio output, virsh console, vnc or sdl
> > > output). I normally use libvirt to manage the guests, but I've
> > > attempted to run qemu manually, and have the same problems.
> > > 
> > > What can cause this?
> > > 
> > > Just tested booting back into the old kernel, the one guest still won't
> > > start, while the rest do. I'm thoroughly confused.
> > 
> > You mean if you only update qemu-kvm, the problem persists, just with
> > lower probability? In that case, we definitely need the version of your
> > current qemu-kvm installation. Also, it would be nice to attach gdb to
> > the stuck qemu-kvm process, issuing a "thread apply all backtrace" in
> > that state.
> > 
> > Jan
> 
> Sorry I wasn't clear. If I just update qemu-kvm (And qemu with it, and not
> the kernel), it always just hangs on load.

where "it" is the one vm I mentioned before. Three others are just fine. The 
stranger bit, is I'm pretty sure I created them all at the same time, in very 
similar ways. At the very least the libvirt config for them all are near 
identical.

[snip]

-- 
Thomas Fjellstrom
thomas@fjellstrom.ca