Hello, I am experiencing an issue with Xen Orchestra (self compiled) not being able to add a new VIF if the VM has a total of 7 VIFs already attached.
I get the following error trying to create the new Network Device:
could not find an allowed VIF deviceThis is only after updating Xen Orchestra to the latest commit (771b04a), before the error was:
INTERNAL_ERROR(Server_helpers.Dispatcher_FieldNotFound("device"))I have tested adding an 8th VIF to multiple VMs using different Networks, but nothing makes a difference. The reason I need that "many" is basically only for the Firewall VM since I am adding a VIF for every Subnet/Vlan in my network. A workaround would be to just attach the trunk to the Firewall VM. However, I would be better if I could attach more than 7 VIFs.
I found this XCP-ng guide stating that 7 VIFs is some limitation in Xen. I think this should be highlighted in the normal Network documentation as well. Can this restriction be changed? Does adding 8+ VIFs via CLI introduce issues like the guide states?
Is there any maximum limitation on how many VIFs are allowed or recommended for a VM in XCP-ng or is this a Xen Orchestra limitation?
The same guide also states that if I want to use the trunk interface inside a VM, that I need to change the MTU of the PIF to 1504. Why is that the case? I changed the 7th VIF (#6) of my firewall VM to a network without any VLAN set (trunk) and now in OPNsense I created a VLAN interface on that network interface. However, that VLAN interface is down and unable to communicate with a VM using a Xen Orchestra network with the same VLAN set. Is this due to the MTU issues? Where exactly do I need to change the MTU, beside on the network switch? I have a LACP (802.3ad) with two SFP+ ports. Do I set 1504 MTU for each of its members, eth0 and eth1, and/or for the bond0 PIF?
Edit: I resolved my last issue, now I can successfully use the trunk port inside OPNsense without having to change the MTU. The issue was me not correctly setting up OPNsense, but now I can ping the firewall from the VM as described in the setup above. Should I still change MTU?