bhyve current windows status

[Peter Grehan]

Hi Matt,

> I'm after some general information on the current status/best practises 
> for Windows on bhyve. Not entirely the correct place for this but then 
> at the moment no-one else seems to really know the answers. Maybe I can 
> help some of the other people who are just as unclear as me on what is 
> actually the best information at this point.

  This is as good a place as any.

> What are the current recommended devices/options for Windows (2019 
> server in my case) - especially with ZFS. Should I be specifying a 
> 512/4096 sector/block size via bhyve and/or zfs? I assume nvme & 
> virtio-net are the current best options but is there a preferred virtio 
> driver version. Are any of the other virtio drivers of any use to be 
> installed or just the network drivers?

  nvme - yes.

  I'll leave the sector/block size issues to others. I don't touch any 
of those params but don't use enough Windows apps to make a qualified call.

  No need for other virtio drivers. For virtio-net, the recommendation 
is to use the latest one.

> Are there any known problems with applications like AD/Exchange? I know 
> that SQL 2012 had massive storage overhead issues on ZFS due to 512 byte 
> writes, but I'm not sure if that still affects newer versions or other 
> applications?

  As above, I'll leave it up to others to chime in here.

> The system I am currently using is a Xeon E5-2670, which I know was 
> terrible before the TPR commit. My test system seems to run reasonably 
> on 12.2 (although I'd be intruiged to compare against ESXi if I had the 
> time), but do you think I would expect to see any significant gains by 
> using a CPU with APICv? (not that I expect anyone has done any 
> benchmarking of this)

  It's been a long while since I've benchmarked APICv, and have never 
benched it on Windows, but my expectation is it won't make a lot of 
difference unless you have a very i/o intensive workload.

> Are there any other changes in being worked on that are likely to have 
> an impact on support or performance?

  No. The main focus for Windows guests right now is GPU passthru.

> I believe quite a bit of work is 
> being done on the UEFI firmware but I expect that doesn't really affect 
> much other than the boot process. I'm sure I saw reference to the devs 
> having regular bhyve calls, but I have little idea what is currently 
> being worked on.

  You can always ask here. For interactive response, there's the bhyve 
office hours which you are most welcome to participate in:
    https://wiki.freebsd.org/bhyve/OfficeHours

later,

Peter.