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Host.<br>
<br>
I'm usually not bother with guest problems. <br>
<br>
I'm not sure, but I think I hit that problem a second time (Fist
time it was during snapshot creation too, but I did not dig deep
enough). <br>
Most obvious symptom is '100% disk utilization' in atop regardless
of actual IO, the second is 'stalled' messages in dmesg after 120
sec.<br>
<br>
<div class="moz-cite-prefix">On 02/09/2014 05:31 AM, Narayan Desai
wrote:<br>
</div>
<blockquote
cite="mid:CABweQmLyA6nuWZCJpuMaK=e8jFroBciv-6ejrmfYsBytzE-kDA@mail.gmail.com"
type="cite">
<div dir="ltr">Host or guest?
<div> -nld</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Sat, Feb 8, 2014 at 6:40 PM, George
Shuklin <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:george.shuklin@gmail.com" target="_blank">george.shuklin@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Can't say
which kernel is stable, but just yesterday I've got rather
unfunny error on my lab stand with 3.8.0-35-generic
(x86_64): vim went to IO and did not come back (in D+
state). Disk was fine, other software was fine, but
in_flight time was 100% for disk and kernel starts to report
'stall' about hanged vim. I played around some time, but
none of tricks was not able to 'free' vim (not the disk
reinitialization, not the pci bus rescan).<br>
<br>
In my case that happens after rather brutal test of
'snapshot creating during 32 concurrent read/write
operations from instance'.
<div class="HOEnZb">
<div class="h5"><br>
<br>
On 08.02.2014 06:02, sylecn wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
<br>
I have experienced "rcu_sched detected stalls on
CPUs/tasks" in ubuntu vms, which result in dead vm
that can't be rebooted/deleted, and I believe it's
because of either bug in hypervisor kernel or guest
kernel.<br>
<br>
I'd like to know which os version and kernel version
do you use in production. Both public and private
clouds are welcome. My company plans to run a small
(to medium) private cloud. Hypervisor runs ubuntu
12.04 and the first guest OSes will be ubuntu 12.04
and CentOS 6. So kernel version for those is much
appreciated.<br>
<br>
Is there a wiki page about this?<br>
<br>
PS. Here is a combination that have the above
mentioned error:<br>
<br>
hypervisor os: ubuntu 12.04.3<br>
hypervisor kernel: 3.8.0-35-generic<br>
vm os: ubuntu 12.04<br>
vm kernel: 3.2.0-56-virtual<br>
openstack: havana<br>
libvirt: 1.1.1-0ubuntu8~cloud2<br>
<br>
Relevant old bugs on similar issues:<br>
rhel5.5 running as kvm guest hangs randomly<br>
<a moz-do-not-send="true"
href="https://bugzilla.redhat.com/show_bug.cgi?id=619798"
target="_blank">https://bugzilla.redhat.com/show_bug.cgi?id=619798</a><br>
<br>
Bug #503138 “Lucid & Natty, KVM, After kernel
message hrtimer: ...” : Bugs : “kvm” package : Ubuntu<br>
<a moz-do-not-send="true"
href="https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/503138"
target="_blank">https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/503138</a><br>
<br>
I don't have a 100% way to reproduce the problem, but
it happens quite often, no matter when the vm is idle
or loaded, which is not acceptable in production.<br>
<br>
<br>
</blockquote>
<br>
<br>
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