vMotion and Storage vMotion are key, widely adopted technologies which enable the live migration of virtual machines on the vSphere platform. vMotion provides the ability to live migrate a virtual machine from one vSphere host to another host, with no perceivable impact to the end user. Storage vMotion technology provides the ability to live migrate the virtual disks belonging to a virtual machine across storage elements on the same host. Together, vMotion and Storage vMotion technologies enable critical datacenter workflows, including automated load-balancing with DRS and Storage DRS, hardware maintenance, and the permanent migration of workloads.
Each vSphere release introduces new vMotion functionality, increased reliability and significant performance improvements. vSphere 5.1 continues this trend by offering new enhancements to vMotion that provide a new level of ease and flexibility for live virtual machine migrations. vSphere 5.1 vMotion now removes the shared storage requirement for live migration and allows combining traditional vMotion and Storage vMotion into one operation. The combined migration copies both the virtual machine memory and its disk over the network to the destination vSphere host. This shared-nothing unified live migration feature offers administrators significantly more simplicity and flexibility in managing and moving virtual machines across their virtual infrastructures compared to the traditional vMotion and Storage vMotion migration solutions.
A new white paper, “VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices”, is now available. In that paper, we describe the vSphere 5.1 vMotion architecture and its features. Following the overview and feature description of vMotion in vSphere 5.1, we provide a comprehensive look at the performance of live migrating virtual machines running typical Tier 1 applications using vSphere 5.1 vMotion, Storage vMotion, and vMotion. Tests measure characteristics such as total migration time and application performance during live migration. In addition, we examine vSphere 5.1 vMotion performance over a high-latency network, such as that in a metro area network. Test results show the following:
- During storage migration, vSphere 5.1 vMotion maintains the same performance as Storage vMotion, even when using the network to migrate, due to the optimizations added to the vSphere 5.1 vMotion network data path.
- During memory migration, vSphere 5.1 vMotion maintains nearly identical performance as the traditional vMotion, due to the optimizations added to the vSphere 5.1 vMotion memory copy path.
- vSphere 5.1 vMotion retains the proven reliability, performance, and atomicity of the traditional vMotion and Storage vMotion technologies, even at metro area network distances.
Finally, we describe several best practices to follow when using vMotion.
For the full paper, see “VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices”.