Red Hat ENTERPRISE 5.4 RELEASE NOTES, Manual

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Chapter 4. Known Issues
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Alternatively, if you're having trouble installing the OS on the virtual machine because of the rtl8139
NIC (for example, because you're installing the OS over the network), you can create a virtual
machine from scratch with an e1000 NIC. This method requires you to have at least one virtual
machine already created (possibly installed from CD or DVD) to use as a template.
1. Create an XML template from an existing virtual machine:
virsh dumpxml GUEST > /tmp/guest.xml
2. Copy and edit the XML file and update the unique fields: virtual machine name, UUID, disk
image, MAC address, etc. NOTE: you can delete the UUID and MAC address lines and virsh
will generate a UUID and MAC address.
cp /tmp/guest.xml /tmp/new-guest.xml
vi /tmp/new-guest.xml
3. Locate the network interface section and add a model line as shown:
<interface type='network'>
...
<model type='e1000' />
</interface>
4. Create the new virtual machine:
virsh define /tmp/new-guest.xml
virsh start new-guest
• Currently, KVM cannot disable virtualization extensions on a CPU while it is being taken down.
Consequently, suspending a host running KVM-based virtual machines may cause the host to
crash.
(BZ#509809)
72
• The KSM module shipped in this release is a different version from the KSM module found on the
latest upstream kernel versions. Newer features, such as exporting statistics on the /sys filesystem,
that are implemented upstream are not in the version shipped in this release.
• The mute button in the audio control panel on a Windows virtual machine does not mute the sound.
BZ#482570
73
• Hot-unplugging of PCI devices is not supported in this release. This feature will be introduced in a
future update.
(BZ#510679)
74
• When migrating KVM guests between hosts, the NX CPU feature setting on both source and
destination must match. Migrating a guest between a host with the NX feature disabled (i.e. disabled
in the BIOS settings) and a host with the NX feature enabled may cause the guest to crash.
(BZ#516029)
75
• the application binary interface (ABI) between the KVM userspace (e.g. qemu-kvm) and the KVM
kernel modules may change in future updates. Using the latest upstream qemu-kvm package is
unsupported due to ABI differences.
(BZ#515549)
76