ESXi 4.1 running FreeNas 8 as a virtual machine - SATA hard drive passthrough ?

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Michael Duraj

Hi All

So currently ESXi 4.1 boots off usb stick
VM DataStore currently 1TB drive contains various virtual machines...

Windows XP
OpenVPN Access Server

1) Asus P6T SE motherboard with Bios setting Intel VT-d [Enabled]
2) vSphere Client -> Configuration -> Advanced Settings (VMDirectPath) -> Intel Corp ICH10 2 port SATA [x] (There are two SATA controllers on board one takes care of 4 ports and the other 2... just using the 2 port to prove a process at the minute) -> Reboot ESSXi
3) freenas vm -> edit settings -> Add -> [PCI Device] -> Intel Corp ICH10 2 port SATA -> Next -> Finish -> OK
4) PowerOn FreeNas VM -> Open FreeNas admin in web browser -> Storage -> Volumes -> Create Volume -> Member Disks <- NO HARD DRIVES AVAILABLE
I have a secondary drive 1TB WB Blue plugged in and ready to go.

Essentially I am trying to use the hardware of one manchine to run mutiple VM's one of them being freeNas, ESXi allows me to give exclusive use (pass-through) use of some hardware, in my case I have chosen one of the SATA controllers and therefore the hard drives plugged into that controller? I have not added any virtual drive to the freeNas VM, I was hoping that in pass-through that freeNas would just see the disk plugged in.


David Fernando

im trying to something like this also. so i am very interested in the answer to this.

Michael Duraj

I think I have to buy a (see Storage Controller) that is supported under;

BUT buying a 4-6 port SATA card expansion card $$ and crossing my fingers and hope that ESXi allows pass-through works.. mighty be better unfortunately to build a seperate box that freeNas can have to itself.
I was hoping that I could simply use ESXi, passthrough USB (freeNas installled here), sata controller and 4-6 hardrives to my freeNAS VM would negate the need for a secondary box..

I also tried giving pass-through access of the sata controller to my Windows XP VM (taking freeNas completely out of the equation).. expecting that when I went into Disk Management that I could see the attached drive.. but no dice. So the issue lies with ESXi <-> Sata Controller.

I also noted that if I re-booted the ESXi machine twice... after changing the pass-through options that my pass-through configuration would be lost.

I watched a youtube clip showing setting up ESXi passthrough of network cards and noted that once setup and post ESXi reboot that the pass-though icon would change to a complete green color.. mine never got to that state. first reboot nothing changed, and then second reboot the pass-through configuration was removed.


Jun 2, 2011
You simply need to export the storage from the FreeNAS box using iSCSI to the VMWare server, and the VMWare server can then setup Virtual Machines on the FreeNAS box the way you want it :)


May 31, 2011
@Soft, I guess the problem here is that FreeNAS is running in the VM and needs access to the drives, not the other way around.


Jun 20, 2011

i'm not exactly sure why you are wanting to do it this way, but if you want direct access to the drive i would suggest using a rdm (raw device map) to the vm. if you are dead set on using the pass-thru you need to make sure your alua configuration for the controller is configured. this is something that would normally be done in esx via the service console to configure multipathing (nmp) & satp via the esxcli command. i don't know how you would go about doing this with esxi outside of the typical hacks to get to the service console. again, i don't think you will get any performance advantages out of doing this over a regular .vmdk file. being able to transplant the physical disk to another box is the only benefit.


I'm playing with exactly this setup and I raw mapped the drives straight through to the VM.
No hardware mapping (my board doesn't support it :( )
It is working fine, I had the drives formatted on a raw freenas8 install and when I reinstalled in a VM, freenas was able to see the drives and the data within.
The speed is cut somewhat, no idea if direct hardware mapping would fix that as my other problem is if I give freenas more than one vCPU, it locks up solid within a very short period of time.
I'm thinking two vCPUs would allow the poor thing at least a little multitasking and help performance some.

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