Assuming that you have a free server available, doing a V2V from Hyper-V to VMware ESXi is extremely easy. Just think of this as doing a P2V, and ignore the wasted resources in between...
Take one of your spare servers, and load up VMware ESXi on it (you can do 4.1 or 5, or whatever strikes your fancy). Get it all ready for the VM to run on it, and get it on the same network and gig switch as your Hyper-V box.
Login to the VM that you want to convert, and download and install VMware's Standalone Converter on it (current version is 5.0). Current supported platforms are:
Next, you will want to run the Converter against the local machine, and convert it to ESXi server that you just created. There are several settings to change to verify that it's done properly:
- Prep your computer for a P2V by stopping ALL unneccessary services. You only need core services to make sure that it's successful.
- Select Powered-on machine; local machine
- Put in the IP/Hostname of your new ESXi server and root/password
- Give it a destination Virtual Machine name
- Select a Resource Pool (if used), datastore, and Virtual Machine hardware version (unless you have a driving reason, go with Version 7)
- Set your disk drives the way that you want them to be on the new environment - I prefer Thin on all my disks, but it's up to you and your application. To change this, Edit the "Data to copy," Advanced, and Destination Layout tab. Change the type to Thin
- Change the Disk controller to SCSI. To change this, Edit the "Devices" and go to the Other tab. I typically select SCSI LSI Logic SAS for newer OSes and SCSI LSI Logic for older OSes.
- Set all services that say Hyper-V to disabled. To do this, Edit the "Services" and go to the Destination services tab. The ones I came across on my most recent migration were (your mileage may vary based on the version/options you have):
- Hyper-V Heartbeat Service
- Hyper-V Data Exchange Service
- Hyper-V Guest Shutdown Service
- Hyper-V Time Synchronization Service
- Hyper-V Volume Shadow Copy Requestor
- Edit Advanced options and go to the Post-conversion tab and check "Install VMware Tools on the destination virtual machine"
Now you can wipe your Hyper-V server, load up ESXi on it, and build yourself a nice little redundant cluster.