Passing disks via motherboard vs IT mode Card

[nanoken]

Hi,

Let's say I wanted to run a Truenas core VM and wanted to pass through 4 Disks and run a ZFS array. Attaching the disks directly seems to still create them as QEMU disks on within the OS. Are there any downsides to this over for example passing through a PCIE card that is attached to the drives so they show up directly?

I don't really want to be leaving performance or overhead on the table here.

Thanks

 

[leesteken]

There is some overhead as the data has to travel via Proxmox but with PCIe passthrough you cannot use ballooning and the VM will always use it maximum memory.
And all the other PCIe passthrough caveats like not working, not working more than once per host reboot... Try both and see what works best for you?

EDIT: Note that this has been asked before on this forum. Maybe this recent thread can help you too?

 

[nanoken]

There is some overhead as the data has to travel via Proxmox but with PCIe passthrough you cannot use ballooning and the VM will always use it maximum memory.
And all the other PCIe passthrough caveats like not working, not working more than once per host reboot... Try both and see what works best for you?

EDIT: Note that this has been asked before on this forum. Maybe this recent thread can help you too?

thanks, I probably won't bother trying the PCIE method if passing disks is somewhat proven and generally okay. I don't have enough PCIE ports currently or the card so I would need a new motherboard