Does OVM / KVM support macvlan?

KVL · Mar 7th 2025

Hello,

I have just configued KVM via the plugin on OMV 7.7

The guests - Windows and Linux - are up running and connected in bridge mode via macvtap. The guest machines can reach all devices on the network, except the host it self.

I have tried to see if it can be bypassed in the firewall, but seems to be the design of macvtap. Alternatives are additional NICs in the guests, or using macvlan. I would like to avoid the extra NIC, leaving it to macvlan. But I dont find anything about in, only in regards to Docker.

Does the OMV / KVM support the macvlan? Do I somehow need to install or load it?

If not, what alternatives do I have to be able to reach the host?

Many thanks K

chente · Mar 9th 2025

Check this https://wiki.omv-extras.org/do…ins:kvm#network_interface

KVL · Mar 10th 2025

Many thanks!

Sounds easy, though, I tried it.

The OMV host has the new interface as the guide describe and is on the net.

I have removed the networks from the KVMs, and tried to add a new network, bridge assigned to br0, as described the the technote.

But it fails, with Error 500 - Unable to add network adapter to VM..

Any clue - or suggestions where to look for further information?

ryecoaaron · Mar 10th 2025

Quote from KVL

But it fails, with Error 500 - Unable to add network adapter to VM..

Any clue - or suggestions where to look for further information?

Can you get the entire error from the bell in the top right of the omv interface?

Was the VM powered off?

Are you able to create a new VM using a bridge? No need to power it on.

KVL · Mar 10th 2025

The only message I got was "Error 500 - Unable to add network adapter to VM". No further information.

I was able to create a new blank VM and assign the Br0 to it without problems.

I removed my existing VMs, and created them again with same specifications, disks etc and could also here assign the Br0 without issues.

So it seems there was some issues on the existing VMs, even I already had all network information removed.

It works now as wanted - they are able to connect to the host - THANKS! But unfortunately I didnt leave much information for further trouble shooting on the issue with the existing VMs.

I am looking forward to see how the Linux and Windows VMs operate and perform - I am only used to work with VMware and VirtualBox.

Thanks again for your help!

ryecoaaron · Mar 10th 2025

Quote from KVL

So it seems there was some issues on the existing VMs, even I already had all network information removed.

I will check it out on my dev machine.

Quote from KVL

I am looking forward to see how the Linux and Windows VMs operate and perform - I am only used to work with VMware and VirtualBox.

I am a VMware admin at work and use the kvm plugin at home. I am actually happier with the kvm plugin than I am VMware (VMware has a lot of issues since the Broadcom purchase).

tchjntr · Mar 25th 2025

Quote from KVL

Many thanks!

Sounds easy, though, I tried it.

The OMV host has the new interface as the guide describe and is on the net.

I have removed the networks from the KVMs, and tried to add a new network, bridge assigned to br0, as described the the technote.

But it fails, with Error 500 - Unable to add network adapter to VM..

Any clue - or suggestions where to look for further information?

Display More

Just happened to stumble upon the same issue.

Here is the full output of the error (you need to check the notifications and copy to clipboard):

Code

Unable to add network adapter to VM -


OMV\Exception: Unable to add network adapter to VM -  in /usr/share/openmediavault/engined/rpc/kvm.inc:386
Stack trace:
#0 [internal function]: OMVRpcServiceKvm->addVmNic()
#1 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array()
#2 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod()
#3 /usr/sbin/omv-engined(544): OMV\Rpc\Rpc::call()
#4 {main}

ryecoaaron · Mar 25th 2025

Quote from tchjntr

Here is the full output of the error (you need to check the notifications and copy to clipboard):

I can reproduce it and am still working on it.

tchjntr · Mar 25th 2025

Can confirm that the quickest way to get past that is to delete the VM (without deleting the storage of course) and then re-create it so you can attach the previous virtual drive and the br0 bridge.

ryecoaaron · Mar 25th 2025

Quote from tchjntr

Can confirm that the quickest way to get past that is to delete the VM (without deleting the storage of course) and then re-create it so you can attach the previous virtual drive and the br0 bridge.

I would just use virt-manager to change the current nic to br0.

ryecoaaron · Mar 25th 2025

So, I don't know why I didn't see the problem before but it jumped right out at me this time. Fixed and will be in the next release

fix adding bridge nic to vm · OpenMediaVault-Plugin-Developers/openmediavault-kvm@5b3d1c3

Signed-off-by: Aaron Murray <plugins@omv-extras.org>

github.com

ryecoaaron · Mar 26th 2025

openmediavault-kvm 7.1.0 is in the repos as of last night.

Does OVM / KVM support macvlan?

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