Since Hyper-V 2008 administrators wishing to migrate VMs from one Hyper-V host to another have been able to achieve this with either a “Quick Migration” or “Live Migration“. Since the introduction of the “Shared Nothing Live Migration” in Windows Server 2012, it has even been possible to migrate a running VM from one host to another with nothing more in common than a basic network connection.
The process involved in migrating a VM is a fairly simple, however to get the environment ready is a little more tricky. This post will step through the configuration required and the process involved in migrating a virtual machine using the “Shared Nothing Live Migration” technology built into Hyper-V on Windows Server 2012 R2.
The process can be broken down into three sections:
- Configuring constrained delegation against each hosts AD account
- Configure the local host settings to enable live migration
- Performing a Shared Nothing Live Migration on a chosen virtual machine
Configure Constrained Delegation:
1. Firstly log into SBHost1 using an account with Domain Admin rights, then open up Active Directory Users and Computers.
2. Locate the AD accounts of the source and target Hyper-V hosts.
3. Right click on the first Hyper-V hosts and select Properties.
4. On the Properties window, select the Delegation tab.
5. On the Delegation tab, select the Trust this computer for delegation to specified services only and Use Kerberos only options and click the Add button.
6. In the Add Servers windows, click on Users or Computers.
7. In the Enter the object names to select window, enter the name of the host you wish to delegate rights to and then click Check Names before clicking OK.
8. In the Add Service window, select the cifs and Microsoft Virtual System Migration Services service types, and then click OK.
9. Back on the Properties windows of SBHost1, check that the service types have been added as appropriate and then click OK.
10. To complete the constrained delegation configuration, repeat the process for the second host. In this example SBHost2.
Configure Host Settings for Live Migrations:
1. Open Hyper-V Manager on SBHost1 and add SBHost2 to Hyper-V manager. This is not essential but it will make the next step a little easier as we can complete all configuration from the one console.
2. Right click SBHost1 and select Hyper-V Settings from the menu.
3. In the Hyper-V Setting window for SBHost1, select Live Migration in the left menu window. In the right window, firstly select Enable incoming live migrations, then select Use these IP addresses for live migration. Finally click the Add button and entering the IP range of the network allowed for Live migrations. In this example 172.16.0.0/16.
4. Click Apply
5. Below the Live Migrations page of the Hyper-V settings menu, expand the Advanced Features page. Select Use Kerberos as the authentication protocol and Compression as the performance option. Click Apply then OK to close the Hyper-V settings window and confirm the settings.
Performing a Shared Nothing Live Migration:
1. From one of the Hyper-V hosts open Hyper-V Manager, right click on the virtual machine you wish to migrate and select Move.
2. On the first page of the Move Wizard, click Next.
3. The next page requires you to chose the type of move you wish to perform. For a Shared Nothing Live Migration select Move the virtual machine and then click Next.
4. Enter the name of the target host in the Name field, and then click Next.
5. Next select how you wish to manage the virtual machines items, such as virtual disk and configuration file. Select Move the virtual machine’s data by selecting where to move the items and then click Next.
6. To move the virtual machine to the target server whilst keeping the same file structure it had on the source server, select Move the virtual machine’s data automatically and then click Next.
7. Review the Summary, then click Finish.
8. Having clicked Finish, the move begins and a process bar is displayed by the Move Wizard.
During the migration, Hyper-V Manager displays the state of the migration by showing the percentage completed. One way to check that the virtual machine remains online during the migration is to connect and monitor it through the console. Another option is to run a ping -t against the virtual machine to confirm there is no drop in connectivity during the migration.
The Shared Nothing Live Migration was a great addition to Hyper-V and well worth playing with if you haven’t already.