From what I understand, the OS-to-iDRAC pass-through is a direct USB link between the host and the BMC, designed for the hypervisor host itself to talk to the iDRAC, not something that would naturally bridge through Xen's networking layer into a VM. That might be why the PIF shows up in XCP-ng but the VM still can't reach 169.254.0.1; the bare metal case works because the OS sits directly on the hardware with no virtualisation layer in between. If you need the VM to have direct BMC access, USB passthrough might be worth exploring; XCP-ng does support passing USB devices through to VMs (https://docs.xcp-ng.org/compute#usb-passthrough), though I'm not certain the iDRAC virtual USB NIC would show up as a passthrough-able device. Might be worth a mention to @Team-Hypervisor-Kernel to find out; others here will know more than me.

@dkg Oops sorry I thought you were someone else having the same issues.

Hello @codemercenary In theory Xen is NUMA aware (See https://wiki.xenproject.org/wiki/Xen_on_NUMA_Machines) so you would leave memory interleaving option of the BIOS off so that Xen does what it thinks is necessary. But these kinds of settings are very very workload sensitive and in fact it's usually a good idea to just test what works best for you. Regards, Yann

@yannsionneau Thank you very much. Please let me know if there’s anything I can help with.

@gleveque Hello Can you retry with an up-to-date XCP-ng 8.3 host? PCI expansion ROM are now enabled when doing pass-through. The guest VM can now access the ROM bar. Regards, Yann

@yannsionneau Thanks for the update! We are eagerly awaiting your findings! Thanks for looking into it.

@Aleksander There are plenty of examples on this forum. We have used Nvidia T4, it works very well.

I've seen this happen after a BIOS update or if a CMOS battery starts failing. Sometimes the motherboard resets to 'Legacy' instead of 'UEFI' (or vice versa), and GRUB just loses its mind because it can't find the partition it expects. It’s worth a quick check in your firmware settings to make sure the boot mode and the drive order haven't shifted on you.

@TeddyAstie I hadn't seen anything special was needed in a VM other that a kernel new enough for support which 6.17 has, is there more to the story with adding things to Ubuntu?

@samuelolavo Thanks for your answer It's very weird because by seeing the command outputs that you pasted, it looks like everything is behaving as it should be. Even the PCI ID (segment:bus:device:function) seems to stay correct (0000:03:00.0) I'll ask others internally.

I am in the same situation as @vhaelan. same as in same iGPU (alderlake) passed-through, same output for those latest commands, same OS (Fedora CoreOS on latest Xcp-Ng stable). Tried current avenues suggested in this thread with no progress. It seems vhaelan has settled with CoreOS under Proxmox (which works!). He also mentioned it works in Debian under XCP-ng, though I haven't tested that myself. I would appreciate additional suggestions for troubleshooting to take this further, in case anyone has any other ideas.

Hi, does anyone have any tips regarding getting the serial port to show up in xcp-ng? I imagine this normally should just work.. I am not sure why it doesnt show up in xcp-ng, while it shows enabled in the bios?

@comdirect Use this command: (replace sda in the command below with the relevant device) cat /sys/block/sda/queue/scheduler The active scheduler will be enclosed in brackets. e.g. noop deadline [cfq] For multiple drives use: grep "" /sys/block/*/queue/scheduler

@stormi Thank you so much. Only now getting around to setting up another set of R660s, will let you know how this works. Edit: worked beautifully on a new set of R660s. Using the old 20250606 ISO, the BCM57414 were not detected. The new ISO works as expected (BIOS install, did not attempt UEFI) and the NICs are all enumerated properly.

@AtaxyaNetwork Hi yes, Sorry I'm not super experienced in this area at all. I'm SSHd into the host and just ran dmesg -T in the root. [image: 1771509732474-0583e493-4d70-40b7-afc0-a88b0d9fd1a4-image.png]

@acebmxer There are older versions of the guest tools still available on Github.

We do upgrade drivers, especially via alt, it's pretty safe (LTS doesn't mean frozen drivers). @stormi could confirm.

Good afternoon, I have resolved the problem. Domo was trying to use the network Controller. Fixed it by using, /opt/xensource/libexec/xen-cmdline --set-dom0 "xen-pciback.hide=(0000:44:00.0)(0000:44:00.1)(0000:45:00.0)(0000:45:00.1)" reboot xl pci-assignable-list Xen Orchestra now allows PCI Networking Card to Pass-Through the VM. Regards

@DustinB said in Recommended DELL Hardware ?: Doesn't using non-shared storage ultimately cause the VM to be started on the other host? No. Live migration can occur between hosts even if: the VDI are located on non-shared storage the hosts are in completely different pools For the cross pool migration to succeed, both pools need to support a common instruction set. Otherwise, use the Warm Migration feature that does reboot the VM so that it is running the correct instruction set on the destination host.