Unable to create device: /dev/kmsg on migrated Ubuntu 14.04 container

LXD
1

I have an old Ubuntu 14.04 server whose hardware I’d like to decommission. I found the helpful lxd-migrate instructions, which I followed and now have an equivalent container to the physical server. The problem is that nothing starts. No daemons, services, etc. It doesn’t even bring up the network. Looking at the output from

$ lxc console somehost --show-log

Console log:

init: Unable to create device: /dev/kmsg

I guess I have no /dev/kmsg. I found here where @stgraber said “there is no /dev/ksmg” but I’m a little unclear what to do next to get past this error and/or have the init process continue.

Thoughts?
-brmiller

2

Hmm, I don’t remember what kind of changes were needed in the upstart days to get things to behave.

I’d probably start by editing /etc/fstab, pretty much removing everything in there and see if that helps.

I don’t think the /dev/kmsg error is the actual issue. I suspect it’s instead waiting for disks to come online and just hanging there.

3

Thank you, Stéphane. Commenting out everything in /etc/fstab did the trick. I took a look at some of my other containers which were created using lxc init or lxc launch and their fstab looked something like

LABEL=cloudimg-rootfs	/	 ext4	defaults	0 0

When using the lxd-migrate tool to create a container, it asks which filesystem to use as root. I naturally chose / which (naturally) copies fstab as-is. Might be a good addendum to the docs to edit this if you do not think this was just me. :slight_smile:

-brmiller

4

@ru-fu we should add something at the end of How to import physical or virtual machines to LXD instances - LXD documentation that the user should expect to have to update some of the configs to match the new environment. Typically storage (/etc/fstab) and network configuration.