Live Migration
Encyclopedia
Live migration allows a server administrator
to move a running virtual machine
or application between different physical machines without disconnecting the client
or application. For a successful live migration, the memory, storage, and network connectivity of the virtual machine needs to be migrated to the destination.
copies all the memory pages from source to destination while the VM is still running on the source. If some memory pages change during memory copy process -- dirty pages, they will be re-copied until the rate of re-copied pages is not less than page dirtying rate .
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
to move a running virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
or application between different physical machines without disconnecting the client
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....
or application. For a successful live migration, the memory, storage, and network connectivity of the virtual machine needs to be migrated to the destination.
Warm-up phase
In memory migration of a VM, usually the Virtual Machine ManagerVirtual Machine Manager
In computing, the Red Hat Virtual Machine Manager is a desktop-driven virtual-machine manager application with which users can manage virtual machines .- Features :Virtual Machine Manager allows users to:* create, edit, start and stop VMs...
copies all the memory pages from source to destination while the VM is still running on the source. If some memory pages change during memory copy process -- dirty pages, they will be re-copied until the rate of re-copied pages is not less than page dirtying rate .
Stop-and-copy phase
After warm-up phase, the VM will be stopped in source and the remaining dirty pages will be copied to the destination and VM will be resumed in destination . The time between stopping VM on source and resuming it on destination is called "down-time". Down-time of a VM during a live migration could be a few millisecond to seconds according to the size of memory and applications running on the VM.Seamless live migration
When down-time of a VM during a live migration is zero or a few millisecond which is not noticeable by end user, it is called a seamless live migration. Otherwise, the end user will feel a small or relatively long glitch in the service.VM managers with live migration support
- Virtuozzo
- XenXenXen is a virtual-machine monitor providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently....
- OpenVZOpenVZOpenVZ is an operating system-level virtualization technology based on the Linux kernel and operating system. OpenVZ allows a physical server to run multiple isolated operating system instances, known as containers, Virtual Private Servers , or Virtual Environments...
- Workload PartitionsWorkload PartitionsAIX Workload partitions are a software implementation of operating system-level virtualization technology introduced in the IBM's AIX 6.1 operating system that provides application environment isolation and resource control....
- Integrity Virtual Machines
- KVMKernel-based Virtual MachineKernel-based Virtual Machine is a virtualization infrastructure for the Linux kernel. KVM supports native virtualization on processors with hardware virtualization extensions....
- Oracle VMOracle VMOracle VM is the server virtualization offering from Oracle Corporation. Oracle VM is based on the open-source Xen hypervisor technology, supports Windows, Linux, and Oracle Solaris guests and includes an integrated Web based management console. Oracle VM features fully tested and certified Oracle...
- POWER Hypervisor (PHYP)
- VMware ESXVMware ESXVMware ESX is an enterprise-level computer virtualization product offered by VMware, Inc. ESX is a component of VMware's larger offering, VMware Infrastructure, and adds management and reliability services to the core server product...
- IBM VPAR with special migrator
- Hyper-V Server 2008 R2
- VirtualBoxVirtualBoxOracle VM VirtualBox is an x86 virtualization software package, originally created by software company Innotek GmbH, purchased by Sun Microsystems, and now developed by Oracle Corporation as part of its family of virtualization products...