FAQ
Since switching from CentOS 5.7 to CentOS 6.x I find that one of the VMs will not restart upon system reboot. I finally figured out that the video is always set to vmvga after rebooting. In addition the VM's storage always reverts back to IDE from virtio and is set to use the wrong image.

It may be related to the fact that I moved the XML files that defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu directory to the new (CentOS 6.2) /etc/libvirt/qemu directory. The images are stored is the same LVM partitions as they were on the CentOS 5.7

Any ideas why a VM would revert back? I've checked the XML file before rebooting and it always has the correct info in it, until after the
reboot.

Emmett

Search Discussions

  • Ljubomir Ljubojevic at Feb 13, 2012 at 6:46 pm

    On 02/13/2012 11:18 PM, Emmett Culley wrote:
    Since switching from CentOS 5.7 to CentOS 6.x I find that one of the VMs will not restart upon system reboot. I finally figured out that the video is always set to vmvga after rebooting. In addition the VM's storage always reverts back to IDE from virtio and is set to use the wrong image.

    It may be related to the fact that I moved the XML files that defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu directory to the new (CentOS 6.2) /etc/libvirt/qemu directory. The images are stored is the same LVM partitions as they were on the CentOS 5.7

    Any ideas why a VM would revert back? I've checked the XML file before rebooting and it always has the correct info in it, until after the
    reboot.
    Do you shutdown that guest system prior to XML changes?

    --

    Ljubomir Ljubojevic
    (Love is in the Air)
    PL Computers
    Serbia, Europe

    Google is the Mother, Google is the Father, and traceroute is your
    trusty Spiderman...
    StarOS, Mikrotik and CentOS/RHEL/Linux consultant
  • Paul Heinlein at Feb 13, 2012 at 6:49 pm

    On Mon, 13 Feb 2012, Emmett Culley wrote:

    Since switching from CentOS 5.7 to CentOS 6.x I find that one of the
    VMs will not restart upon system reboot. I finally figured out that
    the video is always set to vmvga after rebooting. In addition the
    VM's storage always reverts back to IDE from virtio and is set to
    use the wrong image.

    It may be related to the fact that I moved the XML files that
    defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu
    directory to the new (CentOS 6.2) /etc/libvirt/qemu directory. The
    images are stored is the same LVM partitions as they were on the
    CentOS 5.7

    Any ideas why a VM would revert back? I've checked the XML file
    before rebooting and it always has the correct info in it, until
    after the reboot.
    Did you copy the XML file from the 5.7 host to 6.3 host as-is or did
    you edit it at all during the migration?

    I've found that I need either to run "virsh define $DOM.xml" and then
    start the new domain or run "virsh create $DOM.xml" and then, once
    it's running, make a trivial change (usually adding an XML comment) to
    the configuration via "virsh edit $DOM" to get things to stick.

    --
    Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/
  • Emmett Culley at Feb 13, 2012 at 7:24 pm

    On 02/13/2012 03:49 PM, Paul Heinlein wrote:
    On Mon, 13 Feb 2012, Emmett Culley wrote:

    Since switching from CentOS 5.7 to CentOS 6.x I find that one of the
    VMs will not restart upon system reboot. I finally figured out that
    the video is always set to vmvga after rebooting. In addition the
    VM's storage always reverts back to IDE from virtio and is set to
    use the wrong image.

    It may be related to the fact that I moved the XML files that
    defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu
    directory to the new (CentOS 6.2) /etc/libvirt/qemu directory. The
    images are stored is the same LVM partitions as they were on the
    CentOS 5.7

    Any ideas why a VM would revert back? I've checked the XML file
    before rebooting and it always has the correct info in it, until
    after the reboot.
    Did you copy the XML file from the 5.7 host to 6.3 host as-is or did
    you edit it at all during the migration?

    I've found that I need either to run "virsh define $DOM.xml" and then
    start the new domain or run "virsh create $DOM.xml" and then, once
    it's running, make a trivial change (usually adding an XML comment) to
    the configuration via "virsh edit $DOM" to get things to stick.
    I did copy the XML files to the 6.2 machine. Then when I found that the VMs would not start because they were set to vmvga video, which doesn't seem to be supported anymore, I changed the XML files to cirrus.

    Then I tried editing the VM using virsh, but still it doesn't persist.

    Hmm. There is only one of the VMs that doesn't persist so I'll try using virsh edit again on that one and make a change as you suggest, just in case I never really changed anything for that VM using virsh edit.

    Thanks,
    Emmett
  • Emmett Culley at Feb 13, 2012 at 8:19 pm

    On 02/13/2012 04:24 PM, Emmett Culley wrote:
    On 02/13/2012 03:49 PM, Paul Heinlein wrote:
    On Mon, 13 Feb 2012, Emmett Culley wrote:

    Since switching from CentOS 5.7 to CentOS 6.x I find that one of the
    VMs will not restart upon system reboot. I finally figured out that
    the video is always set to vmvga after rebooting. In addition the
    VM's storage always reverts back to IDE from virtio and is set to
    use the wrong image.

    It may be related to the fact that I moved the XML files that
    defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu
    directory to the new (CentOS 6.2) /etc/libvirt/qemu directory. The
    images are stored is the same LVM partitions as they were on the
    CentOS 5.7

    Any ideas why a VM would revert back? I've checked the XML file
    before rebooting and it always has the correct info in it, until
    after the reboot.
    Did you copy the XML file from the 5.7 host to 6.3 host as-is or did
    you edit it at all during the migration?

    I've found that I need either to run "virsh define $DOM.xml" and then
    start the new domain or run "virsh create $DOM.xml" and then, once
    it's running, make a trivial change (usually adding an XML comment) to
    the configuration via "virsh edit $DOM" to get things to stick.
    I did copy the XML files to the 6.2 machine. Then when I found that the VMs would not start because they were set to vmvga video, which doesn't seem to be supported anymore, I changed the XML files to cirrus.

    Then I tried editing the VM using virsh, but still it doesn't persist.

    Hmm. There is only one of the VMs that doesn't persist so I'll try using virsh edit again on that one and make a change as you suggest, just in case I never really changed anything for that VM using virsh edit.

    Thanks,
    Emmett
    Still doesn't persist. Each time I reboot I have to use virt-manager to change video to cirrus from vmvga, then remove the IDE driver that points to the wrong storage location and add a new virtio storage device pointing to the correct image (an LVM partiiton).

    After I make the changes I close virt-manager and restart it, then look at the configuration for the non-persistent VM, and my changes are still there and I can run the VM.

    I did a "grep vmvga" on the entire /etc/libvirt directory tree and found no references to "vmvga". Where can libvirt be getting info to change the xml to vmvga, or the IDE to the wrong location?

    Emmett
  • Paul Heinlein at Feb 14, 2012 at 1:58 pm

    On Mon, 13 Feb 2012, Emmett Culley wrote:

    Still doesn't persist. Each time I reboot I have to use
    virt-manager to change video to cirrus from vmvga, then remove the
    IDE driver that points to the wrong storage location and add a new
    virtio storage device pointing to the correct image (an LVM
    partiiton).

    After I make the changes I close virt-manager and restart it, then
    look at the configuration for the non-persistent VM, and my changes
    are still there and I can run the VM.

    I did a "grep vmvga" on the entire /etc/libvirt directory tree and
    found no references to "vmvga". Where can libvirt be getting info
    to change the xml to vmvga, or the IDE to the wrong location?
    I've not seen these symptoms, so I can only outline the sorts of steps
    I'd take in troubleshooting. First, I'd check for SELinux issues:

    1. Run "fixfiles check /etc" to see if a configuration file is
    mislabled.

    2. Do the same thing on /var to see if any runtime files have
    issues.

    3. Run "ausearch -m avc" and grep for qemu or libvirt issues.

    After that, I'd get more drastic:

    1. virsh shutdown $DOM.
    2. virsh dumpxml $DOM > /tmp/dom.xml
    3. virsh undefine $DOM
    4. virsh create /tmp/dom.xml
    5. virsh edit $DOM
    6. virsh start $DOM --console

    And then see if things get better.

    --
    Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/
  • Florian La Roche at Feb 15, 2012 at 2:33 am

    After that, I'd get more drastic:

    1. virsh shutdown $DOM.
    2. virsh dumpxml $DOM > /tmp/dom.xml
    3. virsh undefine $DOM
    4. virsh create /tmp/dom.xml
    5. virsh edit $DOM
    6. virsh start $DOM --console

    And then see if things get better.
    I just edit the xml files and then issue a "virsh define <file.xml>"
    to reload the newest version. (Doing this with the VM shutdown.)

    This has always worked ok for me.

    best regards,

    Florian La Roche

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupcentos @
categoriescentos
postedFeb 13, '12 at 5:18p
activeFeb 15, '12 at 2:33a
posts7
users4
websitecentos.org
irc#centos

People

Translate

site design / logo © 2022 Grokbase