Live Migration Of Virtual Machines To Transfer Hosts Between VM’s.

Live Migration Of Virtual Machines To Transfer Hosts Between VM’s.

VIRTUAL MACHINE MIGRATION

• Moving a host from one virtual machine to another.
• It is used for maintenance, load balancing etc.

Types:

• Cold migration: the virtual machine is switch off on one host and started on the second.
• Warm migration: to suspend the VM on first host, copy the registry of RAM and CPU and continue withthe second.
• Live migration: transfer of the VM without closing the client or application. It allows proactive maintenance.
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It is based on how the copy is done:

1)Pre-copy memory migration.

WARM UP PHASE

Hypervisor copies the memory pages from source to sink with the VM running. If the pages change then they will be copied again.

STOP AND COPY PHASE

Here the VM will be stopped and the pages will be copied. Then the VM is resumed in the destination. This time between the stop and resume is called the down-time.

2) Post-copy memory migration Here the VM is suspended at the source. A subset of the execution state if sent to the sink. VM will be resumed in the destination. When the down-time in live migration is not noticeable then it is known as seamless live migration. Below is a list of some VM managers that support live migration

–> Workload partitions.

 –>Oracle VM Server for x86.

• Xen
• Virtuozzo.
• Parallels cloud Server.
• Hyper-V Server 2008 R2.
• VirtualBox.
• Oracle VM Server for SPARC.
• Integrity Virtual Machines. Some cloud platforms that support live migration
• Jelastic
• Google Cloud Platform. Some systems providing live migration
• MOSIX
•  Single-system image
• OpenSSL