Slackware-current, migration from LXC 2 to LXC 4

petejc · 08-30-2021, 04:27 PM

Any ideas on the least painful way to migrate from LXC2 to LXC4? On updating my machine today I, unusually, found a number of issues. The main one was that LXC had been updated to LXC 4 and it barfed on the config files and would not start and of the containers.

Googling did show a lxc utility to update the config files, but I had no luck with that - perhaps I was not using it correctly? I also had some issue with library dependencies, I suspect unrelated. Given that I needed to get stuff done I rolled back to a pre-update snapshot (I'm using btrfs for root).

Any thoughts on the least painful way to update my lxc configuration? Googling seemed to show very little on the topic which I found strange. Unfortunately it does not look like I could run lxc 2 and lxc 4 side by side to ease the transition.

My thoughts are holding off updates and basically waiting for Slackware 15 to be formally released and dual booting to a fresh install? Or perhaps blacklisting lxc in slackpkg - assuming that I can fix the other library problems.

Any better ideas?

Pete

Chuck56 · 08-30-2021, 04:59 PM

I'm not using LXC 4.x yet but this recent thread has some insights:

https://www.linuxquestions.org/quest...nt-4175697576/

oily · 08-31-2021, 05:05 AM

There have been quite a few syntax changes between LXC 2 and 4, some of them really minor, for example:

Code:

lxc.utsname

becomes

Code:

lxc.uts.name

while

Code:

lxc.mount

becomes

Code:

lxc.mount.fstab

and

Quote:

lxc.tty

becomes

Code:

lxc.tty.max

The man pages are quite helpful so you should be able to identify most if not all of the changes with them. It's also useful to start containers in foreground mode, you'll get more info on errors that way. You may need to iterate a few times.

petejc · 08-31-2021, 01:52 PM

Quote:

Originally Posted by Chuck56

I'm not using LXC 4.x yet but this recent thread has some insights:

https://www.linuxquestions.org/quest...nt-4175697576/

Thanks, I spotted that but it looked like a discussion regarding patching slackware lxc for systemd and its impact on elogind - which is not my pressing issue.

petejc · 08-31-2021, 01:54 PM

Quote:

Originally Posted by oily

There have been quite a few syntax changes between LXC 2 and 4, some of them really minor, for example:

Code:

lxc.utsname

becomes

Code:

lxc.uts.name

while

Code:

lxc.mount

becomes

Code:

lxc.mount.fstab

and becomes

Code:

lxc.tty.max

The man pages are quite helpful so you should be able to identify most if not all of the changes with them. It's also useful to start containers in foreground mode, you'll get more info on errors that way. You may need to iterate a few times.

Thanks. I thought someone would have written a quick start at some point. But looking at the manpages combined with the errors, as you suggest, seems to be a plan.

Pity I could not run 2 and 4 alongside - but that is an odd use case that only is useful for migration.