Show Table of Contents
20.19. Memory Balloon Device
A virtual memory balloon device is added to all Xen and KVM/QEMU guest virtual machines. It will be seen as
<memballoon> element. It will be automatically added when appropriate, so there is no need to explicitly add this element in the guest virtual machine XML unless a specific PCI slot needs to be assigned. Note that if the memballoon device needs to be explicitly disabled, model='none' may be used.
The following example automatically added device with KVM
...
<devices>
<memballoon model='virtio'/>
</devices>
...Figure 20.67. Memory balloon device
Here is an example where the device is added manually with static PCI slot 2 requested
...
<devices>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</memballoon>
</devices>
</domain>Figure 20.68. Memory balloon device added manually
The required
model attribute specifies what type of balloon device is provided. Valid values are specific to the virtualization platform are: 'virtio' which is the default setting with the KVM hypervisor or 'xen' which is the default setting with the Xen hypervisor.
Where did the comment section go?
Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.