From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: setting time in guest with ntpdate results in VM hang Date: Mon, 27 Aug 2012 16:51:51 -0300 Message-ID: <20120827195151.GA32166@amt.cnet> References: <5037A46F.7050104@sedsystems.ca> <20120824194345.GA16662@amt.cnet> <503BA71C.4000602@sedsystems.ca> <503BC919.5020508@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dale Swanston , kvm@vger.kernel.org To: David Ahern Return-path: Received: from mx1.redhat.com ([209.132.183.28]:39479 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754632Ab2H0Uym (ORCPT ); Mon, 27 Aug 2012 16:54:42 -0400 Content-Disposition: inline In-Reply-To: <503BC919.5020508@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Aug 27, 2012 at 01:23:05PM -0600, David Ahern wrote: > On 8/27/12 10:58 AM, Dale Swanston wrote: > >Good idea. I'll try that. > > > >But are there any tools available to determine what the VM is doing when > >it appears hung? I've looked but haven't found much on debug or > >diagnostics on a running VM. Any links? > > If you have the vmlinux, enable the gdbserver stub via Qemu's > monitor. Then use 'gdb vmlinux', connect to the VM 'target remote > host:port' and look at the backtrace. Another option is to boot the host with profile=kvm, wait for the guest to hang, then do: readprofile -r ; readprofile -m System-map-of-guest.map > I have seen something similar using kvm-clock in a guest running 2.6.27. > > David