# Migrating KVM to bhyve



## James Taylor (Jun 27, 2016)

I could use some advice.

I'm running CentOS on a Lenovo TS140 at home, complete with KVM and ZFS (several VMs on zvols). It has three disks, one for the operating system and two for VMs in a zraid1 pool. All the VMs are either GNU/Linux or a *BSD variant and use bridged networking. It works really well, but I also realize that there's probably not a huge number of compelling reasons to keep it running GNU/Linux. It would be nice to see how it handles a similar setup with FreeBSD as the host operating system instead.

So my question is, are there likely to be any surprises if I install FreeBSD to the boot drive and try to run the VMs  in bhyve, provided I make each VM's configuration roughly equivalent to how it was on KVM? They don't need to do anything interesting like PCI passthru, if that matters. Let me know if you need more information.


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## windscape (Jun 28, 2016)

It should be relatively straightforward to move the VMs to a FreeBSD host. Bear in mind that currently bhyve does not have emulated graphics, so the VMs will need to be reconfigured to use the serial port as the console.


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## James Taylor (Jun 29, 2016)

That definitely presents another interesting option, gpatrick. I appreciate it. 

Yeah, I thought about the lack of graphics, but thankfully these VMs are almost always accessed by ssh or vnc rather than using an SDL display. I'm glad that the migration idea doesn't appear to be an insane proposition!


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## usdmatt (Jun 29, 2016)

I've run VMWare virtual machines on bhyve without any trouble. You'll need to convert the disk images to raw format if they aren't already though.


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## James Taylor (Jun 29, 2016)

Right you are, usdmatt. See, that was part of what drew me to bhyve, knowing that being able to run VMs from ZFS volumes has (as far as I know) always been a priority. It's not that KVM can't do that, it's just that the support for ZFS on GNU/Linux is and perhaps always will be a step behind that of FreeBSD. When there's a particular technology you love, it makes sense to use it in an environment where it's a first-class citizen.

So, I decided to make the plunge last night, did a little reconfiguring, and now I've got a functional FreeBSD setup. There will be much virtualization when I get home later today.


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