IOMMU passthrough HDD

[kssathishmail]

Hi,

I want to learn Proxmox. Did a fresh install to bare metal. Installation and VM creation are successful. Now, trying to Passthrough HDD to VM (Freenas installed). failed to make it work. I have gone through many tutorials, forums, etc to implement/configure IOMMU. But no success. Getting the following message while trying to passthrough the HDD.



Hence, creating this post. Need help. Thanks in advance.

 

[mira]

You want to pass a HDD (not an NVMe) through to your VM?
That's not PCI Passthrough then, and doesn't require IOMMU.

Have you seen the following Wiki entry? https://pve.proxmox.com/wiki/Passthrough_Physical_Disk_to_Virtual_Machine_(VM)

 

[peter247]

Hi,

I want to learn Proxmox. Did a fresh install to bare metal. Installation and VM creation are successful. Now, trying to Passthrough HDD to VM (Freenas installed). failed to make it work. I have gone through many tutorials, forums, etc to implement/configure IOMMU. But no success. Getting the following message while trying to passthrough the HDD.

View attachment 33612

Hence, creating this post. Need help. Thanks in advance.

use eg , qm set 102 -scsi2 /dev/disk/by-id/ata-xxxxxxxxxxxxxxxxxxxxxxxxxx

first you need to find the disks id by ,"ls -l /dev/disk/by-id" , then which VM to send it too eg 102 , the scsi2 the second drive , if you need more repeat and increase the scsi number .

 

[kssathishmail]

use eg , qm set 102 -scsi2 /dev/disk/by-id/ata-xxxxxxxxxxxxxxxxxxxxxxxxxx

first you need to find the disks id by ,"ls -l /dev/disk/by-id" , then which VM to send it too eg 102 , the scsi2 the second drive , if you need more repeat and increase the scsi number .

Thank you so much. I followed your instruction. Added the disks directly to FreeNAS and everything working great.

 

[Kasimir]

Hi there!
I would like to follow up with the question.


I used the qm set function for my setup. Everything is fine. But my Truenas then only see virtual devices. As far as I understand it, every command goes through proxmox itself to access the hdds, which unnecessarily takes more time. With iommu it is possible to pass through the PCI controller so that the VM can talk directly to the hdds.

 

[peter247]

Hi there!
I would like to follow up with the question.


I used the qm set function for my setup. Everything is fine. But my Truenas then only see virtual devices. As far as I understand it, every command goes through proxmox itself to access the hdds, which unnecessarily takes more time. With iommu it is possible to pass through the PCI controller so that the VM can talk directly to the hdds.

I guess the answer is it depends on the controller and if you can separate your proxmox boot drive from what you are passing via iommu.
if you are booting from a nmve drive you should have a free sata controller to pass, but looking at my system most of the chip set is on the same iommu group .
The easiest way is to get a HBA card and pass the full card , But they are PciE 3x8 which odds on means you are using the PciE 16 line video slot.
Not saying it would work but you could use a "4 Port NVME to SATA3.0 M.2 SATA3 Expansion Card for SSD Adapter High Speed"