Live migration allows virtual machines (VMs) to be moved between host servers without being powered off, providing very short downtimes on the order of milliseconds. This is done using shared storage, such as iSCSI or SMB 3.0, accessed by both hosts. It allows VMs to be migrated without interrupting applications. Quick migration in earlier versions required powering down VMs during migration, taking seconds. Live migration enables load balancing and maintenance with minimal impact on users.

1. Hyper-V Live Migration
with Windows Server 2012
Lionel Shaul – Senior Instructor / Corporate Infrastructure Manager

2. What is Migration?
• Migration is moving a VM from one host to another
• Migration can be done when the VM is either powered on or off.

3. Live Migration
• Live Migration implies the VM is moved to another host without
being powered off.
• The VM is inaccessible for a very short period of time (on the order of
milliseconds)
• VMware calls this vMotion.

4. Quick Migration
• Quick Migration was Microsoft’s predecessor to Live Migration.
• The VM was actually powered down, moved and then powered up.
This process occurred over a period of seconds.

5. Why is the speed of the migration
important?
• If the migration occurs quickly enough, applications on the VM will
not time out.
• This will allow the migration of VMs during regular business hours.
• VMware has done this for years.
• VMware does load balancing of hosts using vMotion. It is called DRS,
Distributed Resource Scheduling.
• Only the most anal of IT shops restrict vMotion to outside of business
hours.

6. Recommended Setup for Live
Migration
• Windows Server 2012
• Failover Cluster
• VMs installed as a role on the cluster
• Shared storage for the cluster members
• CSV (Cluster Shared Volumes) to store VMs

7. Shared Storage
• Can use FC (fibre channel), iSCSI or SMB 3.0
• Windows Server 2012 can be both an iSCSI Target and Initiator
• iSCSI is less expensive to implement than FC.
• NFS is not supported for Failover Clustering.
• SMB 3.0 is relatively new, many SANS may not yet support it.
• RemoteDMA nics employing infiniband are very fast, (40 +Gbs) and
can support SMB 3.0. Watch for their prices to drop.

8. CSV Cluster Shared Volumes
• As the name applies, CSV are cluster aware.
• CSVs permit multiple hosts to access the file system simultaneously.
• This eliminates the need to have each VM on a separate LUN.
• VMware’s file system, VMFS, has always had this functionality

9. Let’s build our demo and test it out.
• Join our hosts to the domain
• Install the Hyper-V role on the hosts
• Create an iSCSI target
• Connect to the shared storage via the iSCSI initiator
• Install the Failover Cluster feature and create a cluster
• Add a VM to the cluster
• Compare and measure the speed of different migration methods.

10. Available Courses
Hyper-V for Windows Server 2012
• Configuring and Administering Hyper-V in Windows Server 2012 (3 days)
Hyper-V for Windows Server 2008
• Implementing and Managing Microsoft Server Virtualization (5 days)