From mboxrd@z Thu Jan  1 00:00:00 1970
From: jens <jens@gis.de>
Subject: maybe stability issues
Date: Wed, 29 Apr 2009 14:26:26 +0200
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Hi,

I maybe notized for me hard to reproduce stability issues with kvm and
therefore I would like to ask the list for a hint how to solve the problem.

The kernel I use for the smp host and guest is a 2.6.29.1 kernel.org
kernel and I compiled kvm-85 with '--with-patched-kernel'. For the three
guests I use the virtio block- and network-device and KVM_CLOCK. The
block-devices are drbd-8.3.1 devices on top of lvm2.

The smp host is equipped with 8G ram and one intel core2 quad cpu at
2.83GHz. Two of the three quests (guest1 and guest2) are assigned 2G ram
and 4 vcpus, the third guest (guest3) is assigned 1G ram and 4 vcpus.

To manage the guests I use virsh 0.6.2 (debian unstable).

Today I noticed that guest2 was not running, I started the guest again
and looked at the logfiles but I couldn't figure out why the guest had
stopped.

To test if a system reboot generally works I opened a console on guest3
and started 'reboot' and the guest shuts down but don't came back to
life again even though 'virsh list' shows guest3 in running state. At
this point I noticed that the smp host consumed much cpu power.

Next I destroyed guest3 using virsh but not only guest3 was destroyed,
guest1 was destroyed at the same time too.

At the moment I have absolutely no idea how to figure out what went
wrong because I'm new to kvm and I found no obvious reason for this
behaviour. The only thing I noticed was the message "hrtimer: interrupt
too slow, forcing clock min delta to 141126894 ns" on the console.

Maybe I just used a unstable combination of kvm modules, virtio driver,
kernel, kvm userland- and libvirt-utilities?

I hope that someone on the list with more experience can point me to the
right direction.

For the sake of completeness I'll attach one config.xml, the three
configs are almost the same.

Greetings
jens


--
<domain type='kvm'>
  <name>guest2</name>
  <uuid>a5bf0d7c-c541-82a8-9241-fc5dbf59beb1</uuid>
  <memory>2096128</memory>
  <currentMemory>2096128</currentMemory>
  <vcpu>4</vcpu>
  <os>
    <type arch='i686' machine='pc'>hvm</type>
    <kernel>/boot/vmlinuz-2.6.29.1-wickie</kernel>
    <cmdline>root=/dev/vda ro console=tty0 console=ttyS0</cmdline>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/bin/kvm</emulator>
    <disk type='block' device='disk'>
      <source dev='/dev/drbd2'/>
      <target dev='vda' bus='virtio'/>
    </disk>
    <disk type='block' device='disk'>
      <source dev='/dev/drbd3'/>
      <target dev='vdb' bus='virtio'/>
    </disk>
    <interface type='bridge'>
      <mac address='de:ad:be:ef:26:11'/>
      <source bridge='kvm-br0'/>
      <model type='virtio'/>
    </interface>
    <interface type='bridge'>
      <mac address='de:ad:be:ef:31:16'/>
      <source bridge='kvm-br0'/>
      <model type='virtio'/>
    </interface>
    <interface type='bridge'>
      <mac address='de:ad:be:ef:62:24'/>
      <source bridge='kvm-br0'/>
      <model type='virtio'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target port='0'/>
    </console>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1'
keymap='de'/>
  </devices>
</domain>