Summary
This FAQ article includes questions related to XenMotion using XenServer 4.0.1. Refer to CTX115716 – Citrix XenServer 4.0.1H FAQ for the full set of FAQs.
Q: What is XenMotion?
A: XenMotion is a feature that allows you to move a running virtual machine (VM) from one physical XenServer Enterprise server to another without any downtime.
Q: Which of your products support XenMotion?
A: XenMotion is only provided in our XenServer Enterprise product.
Q: What are the requirements to enable XenMotion?
A: You need at least two XenServer Enterprise servers running in a resource pool.
The XenServer Enterprise servers must have similar processor configurations, some type of remote shared storage such as iSCSI or Network File System (NFS), and a gigabit network connecting them.
Q: How similar do the processors need to be on the XenServer Enterprise servers?
A: To use XenMotion, the processors must 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 Xeon 5130 and Xeon 5140 processors. The same is true of AMD processors.
Q: Can you XenMotion a VM between an Intel and AMD system?
A: No. You can only XenMotion a VM between systems with the same processor manufacturer and type.
Q: Does XenMotion require you to have the same exact configurations for your server systems?
A: 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.
Q: What type of storage does a VM need to be stored on to enable XenMotion?
A: A VM must be stored on remote shared storage to allow for XenMotion.
Examples of this are connections to NFS- or iSCSI (through a software iSCSI initiator)-based storage.
Q: What networking speed is required for XenMotion?
A: We recommend that you use Gigabit Ethernet between your physical servers.
Q: How much downtime occurs during a XenMotion?
The actual downtime during a XenMotion is generally 100-150ms. This downtime is so slight that services running in the VM are not interrupted. Most of the 100-150ms downtime is caused by your network switching equipment moving traffic to a new port.
