Failed adding NIC netdev: Monitor is disconnected

Upstream issue https://gitlab.com/qemu-project/qemu/-/issues/1486

Issue also posted here https://github.com/lxc/lxd/issues/11482

@pgregoire, strangely I started to see the issue now, have you come up with any workaround?
@tomp did some latest commits from the latest/edge channel changed qemu version to 7.2?

Thanks

This is because the latest/edge channel has been updated to QEMU 8.0 which still has the issue.
We have a workaround at the moment (disable the vhost-dev accelerator option), but we are investigating a proper solution. This should also solve the QEMU 7.2 issue too.

Are you planning to apply the workaround to edge snap before the weekend or should one use that?

sudo usermod -a -G kvm lxd

as described in https://github.com/lxc/lxd/issues/11482#issuecomment-1511561446

This PR works around the issue temporarily by disabling the vhost accelerator, which we plan to merge shortly:

Hi,

Sorry for the question but is there any chance you will include the commit from this PR in snap edge channel anytime soon?

Unfortunately there is no option to temporarily downgrade to stable channel due to differences in db backend :neutral_face: and right now vms in edge channel have been unusable since Friday noon

Thanks

It will be included in next snap latest/edge rebuild automatically.
This should be imminently, but it depends on the queue for snap rebuilds.

If you’re relying on LXD to function then we wouldn’t recommend running on the latest/edge channel as its inherently unstable (although it is gated via our normal test suite, but this doesn’t include VM operations).

See Managing the LXD snap

By the way, is there any documentation on how one can build/test lxd snap to possibly contribute :slight_smile: ?
I assume there must be some example snapcraft.yaml somewhere or am I wrong?

You actually don’t need to build the snap, just the lxd binary and sideload it into the snap, see How to create LXD binaries from the source code and side load them in an existing snap installation

Thank you for the information, now I am using the hold option but it’s crying over spilt milk I guess.

Is there any option to temporarily move the existing envitonmet to the stable channel to work there?
I found an old post saying that downgrading to stable is impossible due to db backend differences. Has anything changed in this regard?

Thanks

Because we’ve just released LXD 5.13, the latest/stable and latest/edge channels should have the same DB schemas and API extensions so you should be able to switch back. Try it, if LXD won’t start then you’ll need to switch to edge again.

Unfortunately that did not work, I will have to wait for next update of latest/edge channel. Let’s hope it will be in snapcraft soon :slightly_smiling_face:

Thanks

Ah I think we must’ve merged an api extension recently for the cluster heal feature.

I even tried snap revert but that must have been merged earlier in time I guess

Just in case if the edge channel does not get update this week, would you rather recommend creating a parallel lxd snap install?
https://snapcraft.io/docs/parallel-installs
Or just export all machines I have and do some kind of fresh install?

Which is in general a safer solution?
Could I e.g create a parallel ceph pool in my existing microceph?

Sorry for these questions I know that I should not have put so much trust in edge channel but right now I would like to minimise the aftermath as much as possible

Thank you

It will get updated this week. We had a dqlite regression that was holding us from doing that update but now we’re just waiting for tests to all clear before it gets auto-updated.

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The edge snap should be functional for VMs again now.

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Thank you guys :slightly_smiling_face: everything works fine now.
I promise to always use the --hold from now on

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