What is XenMotion?

XenMotion is a feature that allows you to move a running virtual machine from one physical XenEnterprise server to another without any downtime.

Which of your products support XenMotion?

XenMotion is only provided in our XenEnterprise product.

What are the requirements to enable XenMotion?

You need at least two XenEnterprise Servers running in a resource pool. The XenEnterprise servers need to have similar processor configurations, some type of remote shared storage such as iSCSI or NFS, and a gigabit network connecting them.

How similar do the processors need to be in my XenEnterprise servers?

To use XenMotion, the processors need to be the same type, but can have slight differences such as CPU speed. So, for example, all the systems would need to have Intel Xeon 51xx series processors. They could be different speeds, so you can mix systems with Intel Xeon 5130 and Xeon 5140 processors. The same is true of AMD processors.

Can you XenMotion a VM between an Intel and AMD system?

No, you can only XenMotion a VM between systems with the same type and manufacture of processor.

While you do need to have the same type of processor in each system, other configurations can differ. You can have different amounts of memory, different storage controllers, and different network controllers in each system.

Can you XenMotion VMs between two systems with the same CPU but different clock speeds?

Yes, the processors need to be the same type, but can have slight differences such as CPU speed. So all the systems would need to have Intel Xeon 51xx series processors. They can be different speeds so you can mix systems with Intel Xeon 5130 and Xeon 5140 processors.

What type of storage does a VM need to be stored on to enable XenMotion?

A VM needs to be stored on remote shared storage to allow for XenMotion. Examples of this are connections to NFS or iSCSI (via Software iSCSI initiator) based storage.

What speed of networking is required for XenMotion?

We recommend that you use Gigabit Ethernet between your physical servers. 

How much downtime will occur during a XenMotion?

The actual downtime during a XenMotion is generally 100-150ms. This downtime is so slight that services running in the VM will not be interrupted. Most of the 100-150ms downtime is caused by your network switching equipment moving traffic to a new port.