In order to migrate vSphere VMs from one vSphere host to another or between vSphere clusters that would cross processor generations or types, a specific set of steps need to be followed to reduce the potential impact to customers.
Before any VM is migrated from one host type to another, the VMware Tools installed on the VM must be running at the latest version available on either the vSphere vCenter Server or the one included with the vSphere Hypervisor. To determine the state of the VMware Tools for a VM, look for the “VMware Tools” line on the VM summary page.
To upgrade the VMware Tools on a VM, right-click on the VM, or multiple VMs from a list, then select “Install/Upgrade VMware Tools” under the “Guest” menu item. If prompted for an installation type, select “Automatic Tools Upgrade” and click OK. The VMware Tools upgrade process will kick off and will automatically reboot the VM once the newer version has been installed.
To properly migrate a VM that resides on a host running on a Dell blade server on to one running on an IBM blade server, and is running the latest available build of VMware Tools, use the following set of instructions:
- Safely shut down the VM either by right-clicking on the VM and choosing “Shut Down Guest” under the “Guest” menu item; or, by logging on to the VM and run the appropriate shut down process.
- Once safely shut down, right-click on the VM to migrate and click on “Migrate…”
- Use the Migrate VM wizard to select the migrate method required (host, datastore or both host and datastore).
- Select the appropriate host and/or datastore destination
- If migrating a VM between datastores, you may be prompted on whether you want to change how the VM’s storage is provisioned (thin or thick). If space is at an absolute premium, select thin; otherwise, select thick provisioning and continue on.
Please note that changing a VM’s storage provisioning can increase the amount of time required to migrate the VM, as the VM’s virtual hard disk files (VMDK) will need to be re-done on the destination datastore.
- Complete the Migrate VM wizard and wait for the process to complete.
- Power on the newly migrated VM and log on using the VM console.
- Upon first log on after migrating a VM between host types, the OS will need to pick up on any underlying hardware changes (such as processor and the “Base System Device” for Windows). For Windows, a reboot is mandatory. For Linux, you may need to go through the hardware add/remove process as the VM boots up.
At this point, migrating a live VM across both servers and datastores is not available. That feature is only available when both hosts are licensed with vSphere Enterprise or Enterprise Plus.
When migrating a VM from a host with AMD processors to a host with Intel Xeon processors, the above steps can be used with the following things to watch out for:
- Depending on the version and service pack level of Windows, multiple reboots may be required once the VM has been powered back on after it has been migrated to an Intel-based host.
- Applications that require software activation and use processor type and UID may need to be re-activated