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In a modern IT environment, it's critical that an administrator is able to migrate between hypervisors as needed, for many reasons. One of the more common migrations is from VMware to Hyper-V, but just because it's a common migration doesn't mean that the process is simple. There are specific steps you have to take beforehand to ensure a successful migration.
First, you need to ask yourself two questions:
1. How many VMs am I migrating? Migration of large estates is more efficiently done using one of the many bulk migration tools available. Each migration equates to downtime, which costs money.
2. How much downtime will my migration require? The time for the migration is directly proportional to the amount of data in the VM being migrated.
Assuming you're only migrating a handful of VMs, the best way to move between hypervisors is to use the tools that the vendors provide.
As a side note, support for Open Virtualization Format (OVF) is baked right into vSphere, so there's a wider range of platforms beyond Hyper-V to which you can migrate VMs.
Hyper-V doesn't include the same built-in OVF support, so Hyper-V requires additional migration steps. Fortunately, Microsoft Virtual Machine Converter allows the import of VMware machines.
What will complicate matters is that the Azure Replica Wizard, which has the OVF support functionality built into it, will supersede the migration tool in 2017. You can use the Azure migration method free for one month -- essentially, an evaluation period. After that, you have to pay to use Azure. In the meantime, I recommend you use Microsoft Virtual Machine Converter, which is what we'll use in the scenario below.
Perform a cleanup
Prior to migrating the VM from VMware to Hyper-V, it's considered good practice to perform a cleanup on the source VM. The steps are as follows:
1. Remove all CD/floppies that are attached. Leaving the media attached reduces the interoperability and can disrupt migrations. When using VMware's latest web client, the OVF will export attached media by default.
2. Review the VM for unneeded hardware. VMs created from a physical-to-virtual process can contain a lot of unnecessary virtual hardware, including sound cards, parallel and serial ports.
3. Clean up the disks. This includes the basic items, such as emptying the trashcan, removing any unneeded applications and so on. It's also considered good practice to perform a defragmentation on the source volumes before migration.
4. Commit any snapshots. Snapshots can't be utilized or exported in the OVF. Deal with this by either committing any snapshots or reverting them as needed.
Once the VM is cleaned up and ready for migration, it's time to export the VM.
It's important to note that only certain versions of ESXi are supported for migration. For example, ESXi 6.5 is not yet supported as a source platform. More information on supported source platforms can be found on the Microsoft site.
Export the VM
To perform an export from VMware to Hyper-V, open Microsoft Virtual Machine Converter. Click through the first introductory page. Under Machine Type, select Virtual machine conversion and click Next.
The next selection is Migration Destination. This allows you to migrate to either an Azure or Hyper-V environment. Select Migrate to Hyper-V, as seen in Figure B, and click Next.
On the next screen, shown in Figure C, select the destination Hyper-V host and the desired user account. In this example, we're logged in as the domain administrator. You can override the logged in account by unticking the Use my Windows user account box.
This next screen, shown below, defines where to upload the converted VMs. You need to configure the destination share in advance so that the user who is doing the conversion has enough rights. Domain admins have full rights on the share below. Leave the rest of the options with the defaults as they are for now.
You must then select the source vCenter or ESXi host. Please note that it works with free ESXi hosts. Here, we're using the domain admin credential to log in to vCenter, so we can see all the machines in the cluster. In any event, the vCenter should use Active Directory authentication in a reasonably-sized environment. You may need to adjust your settings as needed. Single ESXi hosts are supported for migrations as well, by using the local ESXi host credentials and the appropriate host name.
On the next screen, shown in Figure E, select the VM. For a successful migration from VMware to Hyper-V, the VMs need to be powered off.
On the workspace screen, select a location for the temporary migrations. It should have plenty of spare space.
Double-check the details on the summary page and click Next. At this point, the migration will begin.
Once the VMware to Hyper-V migration is complete, the Hyper-V server will bring up the guest -- that is, if the option was selected. The VMware Tools service will pause. Once the boot up is complete, VMware Tools should be removed.
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