VMware to Hyper-V migration less time

[StanoSedliak]

Hi,

I would like to ask for a hint if someone has a procedure how to migrate vmware VMs to Hyper V with min. outage for customers.
I know Instant recovery, but do someone has a hint if there would be a possibility to make some initial restore to hyper-v than mapp some replica from prod VM Vmware to min. downtime. Any hints? thank you!

[BackupBytesTim]

I've actually never tried with Veeam, nor looked it up, but my first thought is to have said VMWare VM backed up, and perform a failover to the Hyper-V server. As if in a disaster recovery situation. This is what I don't know if Veeam does though, can Veeam launch a virtual machine from a backup file or would Veeam have to convert the backup file to a regular disk first, as in a standard recovery operation? I assume Veeam's DR operations work somehow off of backup files, wouldn't be very efficient if the backup files had to first be converted to regular disks before the VMs could be started, but I'm not sure. Never actually tried, almost all of our customers are physical computers only.

[tyler.jurgens]

Instant recovery is your best bet, because that creates the VM and the appropriate Hyper-V VHDs from the backup of VMware's vmdk's. You're just going to have to plan an outage window at this time.

[BackupBytesTim]

From reading the explanation there, it seems that the Instant Recovery feature isn't actually "instant"? Or am I mistaken, if it has to convert the backup to a virtual disk and restore said virtual disk to a particular server, that's hardly "instant". Or am I misunderstanding how that works?

My expectation, and what I would do using different software if in the same situation, is to have a backup of the VMWare VM, and then boot the new Hyper-V VM from the backup file itself, without converting it or moving to different storage. Which is much more "instant" in my opinion. Does Veeam not also have that ability?

[RobMiller86]

We've been doing this with minimal, but not zero downtime, using IR. Backup the VMware VM, and during a maintenance window, power down the original on VMware, and run an IR back to Hyper-V. 10-15 minutes of downtime regardless of the size of the VM. Then migrate to production in the background. The disks have to be converted, so we found this method to work the best for us.

[BackupBytesTim]

That sounds about what I was expecting to be able to do there. Not sure there would be a way to actually zero downtime at all, since at some point you do need to swap VMs, though now I'm curious if there's maybe some tool out there that can do a live migration between ESXi and Hyper-V. Especially with recent changes to VMWare's customer base, it could be a more used thing for people migrating away from ESXi.

[f.neumann]

If a downtime of around 15min on such migration task is too long for your environment you probably need to adjust redundancy on software level. So having 2 Domain Controllers results in no downtime even if one is turned off. Same for SQL-Cluster, Fileserver-Cluster,… Design it that way and you keep up production workloads even if one vm is turned off due to migration, patch-installation, …
Haven’t seen VM-Level replication between HyperV and VMware so far. You might create VMware Host on HyperV in Nested virtualisation, to move workload to another host and then maybe reduce downtime further - but probably not worth the effort!