VMWare C236M-WS passthrough of onboard controller?

[devilkin]

Hi folks,

Looking at a new build, I got recommended to investigate the possibilities of running FreeNAS in a VM.
The board i'm looking at is the Asrock C236M-WS, which has the C236 chip. It has 8 Sata ports and also support for an M.2.

I'm wondering if I could use the M.2 to boot esxi from, and then passing the actual SATA ports through to FreeNAS.

The schematic in the manual isn't too clear on wether or not this will be possible. Anyone that can chime in?

 

[sretalla]

It's often not possible when the SATA ports are coming from the chipset... more likely to work is where the SATA ports come from a separate SATA or SAS controller chip on the board... someone else may be able to confirm from actual experience that it does or doesn't work, but my guess is that it won't.

Perhaps an outside chance would be to boot from USB (since the M.2 slot probably supports SATA mode from the chipset), which may leave the controller free to be passed through.

 

[Yorick]

No reason to use SATA mode for an M.2, it can just be used with PCIe/NVMe. That said, while people have passed onboard SATA ports through, I too do not know how well that works on C236.

What’s the intent behind this design? Where will ESXi get its storage from? What kind of guests will run on this?

While it’s possible to virtualize FreeNAS, understand it comes with its own pitfalls and you are not likely to get support for that design from this forum, only because most people here are hobbyists on bare metal, and those that do run virtualized put a limit on how much free support they are willing to give for something this complex.

Since you have a small board with just a little bit of RAM, the question is whether you couldn’t achieve what you want without the added complexity of ESXi.

 

[sretalla]

No reason to use SATA mode for an M.2, it can just be used with PCIe/NVMe

I wasn't suggesting that, more that the option for the M.2 port was probably there, so the onboard controller probably had a link to it, meaning if it was used for boot (even in NVME mode), perhaps the chipset SATA was already out of play for passthrough.

 

[devilkin]

What’s the intent behind this design? Where will ESXi get its storage from? What kind of guests will run on this?

The idea is to have ESXi get it's storage (via NFS) from FreeNAS. The point that I want to use some form of hypervisor is that I do want to run some VM's on the same hardware, be it through bhyve or by using a hypervisor in front. The overhead of bhyve is rather big.

 

[Yorick]

I see some complexities. If the storage is via FreeNAS and FreeNAS is a VM, where will its boot files be stored? Can you delay the other guests starting until FreeNAS is up? Since you are using NFS, will you turn off sync write? If not, will you pass through a SLOG?

I do want to run some VM

Yes, that was my question: Which, specifically? OS and app?

bhyve isn't the most flexible and, the added complexity of running FreeNAS as a VM isn't just rather big, it's huge. Are you ready for that?

Edit: Are you married to ESXi and FreeNAS? Proxmox supports ZFS, a straight "just Proxmox" build might be less complex and get you both solid virtualization and ZFS.

 

[devilkin]

I see some complexities. If the storage is via FreeNAS and FreeNAS is a VM, where will its boot files be stored? Can you delay the other guests starting until FreeNAS is up? Since you are using NFS, will you turn off sync write? If not, will you pass through a SLOG?

I see less issues there to be honest. Depending on what is possible with the chipset (which I can't figure out at the moment due to not having the hardware and not finding much online), using the m.2 for esxi/data volume for FreeNAS and passing the rest through, or using an HBA.

For the startup delay - that is an interesting one. VM interdependencies are possibilities, together with startup delays. As this is for a home (not a production environment) I could just manually start the VM's. There are probably solutions out there.

To be honest - NFS was one idea - iSCSI probably is a better one.

Yes, that was my question: Which, specifically? OS and app?

We're talking small scale VM's here:
- one unifi controller (linux, 2gb, java based app)
- 3-4 more linux vm's running small things, 2-4 gb of ram allocated
- one linux VM for docker containers
- one or two windows10 VM's

bhyve isn't the most flexible and, the added complexity of running FreeNAS as a VM isn't just rather big, it's huge. Are you ready for that?

I like a challenge ;) though it's important that the solution is stable.

 

[Yorick]

Well, have at it, and use the virtualization Resource section. Good luck!