Status of bhyve

Harry Schmalzbauer freebsd at
Thu Feb 16 09:46:39 UTC 2017

 Bezüglich Andrea Venturoli's Nachricht vom 15.02.2017 19:41 (localtime):
> Hello.
> I've been searching the web for a while, but the info I got is sparse
> (many howtos, little on the big picture) and it's not always clear
> what is current and what is outdated.
> I might be in need to permanently run a Windows 64b VM (with SQL
> server) on a new FreeBSD box, so...
> What's the current status of bhyve?
> I mean, it is it production ready (meaning no critical feature is
> missing and I can count on this VM to behave properly nearly as much
> as the host)?

it depends on the features you need.

I do have one byhve in production instead of ESXi.
But some features are incomplete/disfunctional, so if you need a host
with more than very basic hypervising capabilities, take these into account:

· virtio-blk and jumbo frames (e1000 works with jumbo frames but
performance is not comparaable with ESXi e1000(e))

· PCI-Passthru is very picky. If you have a card with BAR memorysize < |
!= pagesize, byhve(4) won't accept it.

· device(9) as block storage backend (virtio-blk, ahci-hd) doesn't work
if you use any PCI-passthru device

· virtio-blk isn't virtio-win (Windows driver) compatible, guest will crash!

· virtio-net doesn't work with latest Windows drivers, which is not a
bhyve(4) problem as far as I can tell. Version 0.1.118 works, newer ones
are known to have problems on other hypervisors too.

· See if_bridge(4) for some limitations (all members need to have
exactly the same MTU, uplink gets checksum offloading disabled).
Generally, soft-switching capabilities ar not comparable with those of
ESXi, especially not the performace (outside netmap world).
In FreeBSD-12 you have ptnetmap, which together with netmap provides
excellent performance, but I have no idea if this will be megred back
into 11-stable, neither if it is production ready.

Other than that, it's rock solid for me

> Any difference between 10.3 and 11.0? (I got the idea the former will
> be supported for longer and I'd have to upgrade my poudriere in order
> to install the latter).

You can seamlessly update minor release versions in the same major
release branch, and there will be a 11.x release wich will also get long
term support. I'd take 11-stable (e.g. yoU'll have ahci,hd|cd so you can
have one virtual controller with multiple devices instead of multiple
controllers), there are snapshots available I think.

> How well does it run Windows?
> Would I better run W7 instead of W10 (or the other way round)?

Both runs fine here utilizing BHYVE_UEFI_CSM.fd, with the limitations
mentioned above (no virtio-blk, need stay with ahci-hd).

> What's the maximum amount of RAM I can dedicate to a VM?
> How does it compare to VirtualBox wrt to stability and performance?
> (I know I can find benchmarks, but, again, it's hard to tell whether
> they can be trusted or considered current).
> Should I use a dedicated disk (or disk mirror) for better speed?
> Or should I use a dedicated partition on the host's disk/disk mirror?
> Will a ZFS volume perform as good as a partition?

ZVOL is the best option offering great performance (depending on your
pool setup of yourse) as long as there is the PCI-passthru bug mentioned

> Any caveat or hint?

Hope the above ones help.


More information about the freebsd-questions mailing list