Somemigration tools do not handle a more complicated VM configuration than a single virtual disk with a simple network configuration without extensive testing and troubleshooting. Be sure to test with a handful of non-mission-critical VMs, one at a time. VMs that have customized configurations or physical disks will require extensive testing. Non-standard configurations can include:
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Physical Access to a disk: in-guest iSCSI, virtual FC HBA, physical RDM, virtual volume
Some tools will uninstall VMware Tools during the migration process, others will disable the VMware services, and some will ignore VMware tools. It is a best practice per Microsoft guidance to uninstall VMware tools in the VM before beginning the migration so that the migrated VM will not boot with VMware tools installed on Hyper-V. Mission critical VMs will require more scrutiny. Some migration tools will migrate without having to power off the VM, and other applications can avoid VM migration by implementing replication from within the application such as with SQL Server Always-On Availability Groups. In that example, new VMs can be provisioned and added to the SQL cluster, and additional secondaries of the Availability Group can be seeded. After failover, the original VMware VMs can be removed from the SQL cluster and decommissioned.
A virtual to virtual (V2V) tool is the least complicated way to migrate a VM from VMware to Hyper-V. The tool enumerates VMs in vCenter, VMs are selected, and the target Hyper-V hosts and file locations are specified. Depending on the VM configuration, a V2V migration may not be possible.
Most V2V solutions require virtual disks, which would be VMDK files on ESXi, and will migrate to VHDX files on the Hyper-V target. Regardless of whether the boot or system disk is a virtual disk, other non-virtual disks may be configured in the VM. These non-virtual disks could include physical RDM, virtual volume (vVOL), in-guest iSCSI, or virtual FC HBA. Most migration tools involve converting the source VM and copying it to the destination Hyper-V host.
In the case of physical disks, convert them to virtual disks with a P2V tool or clone them on the FlashArray, and attach them to the destination VM on the Hyper-V host. Ensure the copied or migrated VM is working perfectly before decommissioning the original VMware VM.
There are three common strategies for migrating these VMs:
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Convert the physical or virtual disks to virtual disks on the Hyper-V platform (VHDX).
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Utilize third party backup software to backup the ESXi VM, and restore it to a Hyper-V server or cluster.
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Clone the physical disks and connect the clones to the migrated VM.