Displaying the current libvirt-internal configuration

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The current libvirt-internal configuration is based on the domain configuration-XML file of the defined virtual server, complemented with libvirt-internal information, and modified as devices are attached or detached.

Procedure

To display the current libvirt-internal configuration of a defined virtual server, use the virsh dumpxml command (see dumpxml):

# virsh dumpxml <VS>

<VS>: Is the name of the virtual server as specified in its domain configuration-XML.

Example

Domain configuration-XML file vserv1.xml configures virtual server vserv1:

vserv1.xml

<domain type="kvm">
  <name>vserv1</name>
  <memory unit="GiB">4</memory>
  <vcpu>2</vcpu>
  <cputune>
    <shares>2048</shares>
  </cputune>

  <os>
    <type arch="s390x" machine="s390-ccw-virtio">hvm</type>
  </os>
  <iothreads>2</iothreads>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>preserve</on_crash>
  <devices>
    <disk type="block" device="disk">
      <driver name="qemu" type="raw" cache="none" io="native" iothread="1"/>
      <source dev="/dev/mapper/36005076305ffc1ae00000000000020d3"/>
      <target dev="vda" bus="virtio"/>
      <boot order="1"/>
    </disk>
    <interface type="direct">
      <source dev="bond0" mode="bridge"/>
      <model type="virtio"/>
    </interface>
    <console type="pty">
      <target type="sclp"/>
    </console>
    <memballoon model="none"/>
  </devices>
</domain>

Device configuration-XML file dev1.xml configures a separate device:

dev1.xml

<disk type="block" device="disk">
  <driver name="qemu" type="raw" cache="none" io="native" iothread="2"/>
  <source dev="/dev/mapper/36005076305ffc1ae00000000000021d7"/>
  <target dev="vdb" bus="virtio"/>
</disk>

You can define and start the virtual server and then attach the configured device with the commands:

# virsh define vserv1.xml
# virsh start vserv1 --console
# virsh attach-device vserv1 dev1.xml

The virsh dumpxml command displays the current libvirt-internal configuration, as for example:

# virsh dumpxml vserv1
<domain type="kvm">
  <name>quickstart1</name> 
  <uuid>4a461da8-0253-4989-b267-bd4db02bfac4</uuid>
  <memory unit="KiB">4194304</memory>
  <currentMemory unit="KiB">4194304</currentMemory>
  <vcpu placement="static">2</vcpu>
  <iothreads>2</iothreads>
  <os>
    <type arch="s390x" machine="s390-ccw-virtio-6.2">hvm</type>
  </os>
  <clock offset="utc"/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>preserve</on_crash>
  <devices>
    <emulator>/usr/bin/qemu-system-s390x</emulator>
    <disk type="block" device="disk">
      <driver name="qemu" type="raw" cache="none" io="native" iothread="1"/>
      <source dev="/dev/mapper/36005076305ffc1ae00000000000020d3"/>
      <target dev="vda" bus="virtio"/>
      <boot order="1"/>
      <address type="ccw" cssid="0xfe" ssid="0x0" devno="0x0000"/>
    </disk>
    <disk type="block" device="disk">
      <driver name="qemu" type="raw" cache="none" io="native" iothread="2"/>
      <source dev="/dev/mapper/36005076305ffc1ae00000000000021d7"/>
      <target dev="vdb" bus="virtio"/>
      <address type="ccw" cssid="0xfe" ssid="0x0" devno="0x0002"/>
    </disk>
    <interface type="direct">
      <mac address="52:54:00:6a:0b:53"/>
      <source dev="bond0" mode="bridge"/>
      <model type="virtio"/>
      <address type="ccw" cssid="0xfe" ssid="0x0" devno="0x0001"/>
    </interface>
    <console type="pty">
      <target type="sclp" port="0"/>
    </console>
    <memballoon model="none"/>
  </devices>
</domain>

libvirt added a number of XML elements to the current representation of the virtual server configuration. They are shown in bold:

A UUID for the virtual server.
The current machine type, which depends on the host setup and distribution.
For devices, the emulator, MAC addresses and address elements.