Installation guide

Chapter 18. KVM live migration
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• Two or more Red Hat Enterprise Linux systems of the same version with the same updates.
• Both systems must have the appropriate ports open.
• Both systems must have identical network configurations. All bridging and network configurations
must be exactly the same on both hosts.
• Shared storage must mount at the same location on source and destination systems. The mounted
directory name must be identical.
Configuring network storage
Configure shared storage and install a guest on the shared storage. For shared storage instructions,
refer to Part V, “Virtualization storage topics”.
Alternatively, use the NFS example in Section 18.2, “Shared storage example: NFS for a simple
migration”.
18.2. Shared storage example: NFS for a simple migration
This example uses NFS to share guest images with other KVM hosts. This example is not practical for
large installations, this example is only for demonstrating migration techniques and small deployments.
Do not use this example for migrating or running more than a few virtualized guests.
For advanced and more robust shared storage instructions, refer to Part V, “Virtualization storage
topics”
1. Export your libvirt image directory
Add the default image directory to the /etc/exports file:
/var/lib/libvirt/images *.example.com(rw,no_root_squash,async)
Change the hosts parameter as required for your environment.
2. Start NFS
a. Install the NFS packages if they are not yet installed:
# yum install nfs
b. Open the ports for NFS in iptables and add NFS to the /etc/hosts.allow file.
c. Start the NFS service:
# service nfs start
3. Mount the shared storage on the destination
On the destination system, mount the /var/lib/libvirt/images directory:
# mount sourceURL:/var/lib/libvirt/images /var/lib/libvirt/images