This set of scripts are for migrating CentOS6 OpenVZ containers to LXC on Proxmox 5. It might work for non-Proxmox LXC as well.

These are untested on any container other than CentOS6. They are also untested under any circumstance other than OpenVZ -> Proxmox5. You might be able to modify them for other circumstances, and I'd accept pull requests if you have success.

I made these because I had 50+ more or less homogenous containers to migrate. They're not guaranteed or foolproof. But my project is complete, and I put the scripts out here in the hopes that they help someone else.

CYA

If you don't review these scripts and test them out in a safe environment first, you're a bad sysadmin and you should feel bad. It should go without saying that there ain't no warranty here, but read LICENSE-COPYING before doing anything else and make sure you understand what it says. I Jeff Tickle of sound mind and body hereby release any and all copyright protection over this work.

How To Use

The stage1 script just rsyncs the contents of your container to another host.

The stage2 script replaces some files to make it work with LXC and Proxmox, and then builds a .tar.xz that can be used as a template to make a new container.

You're going to want to use SSH keys, private key on openvz, public key on proxmox0. Root to root.

Deploy the files directory from this repository somewhere on your proxmox host. I used /root/migrate/files for the files directory, and /root/migrate/work for the working directory where it messes with your container files.

Configure the Scripts

In proxmox-convert-stage1.sh:

1. PRIVATE should be set to your OpenVZ private base directory, usually /vz/private
2. WORKBASE should be set to the remote user and host and path that you want to work inside of on the proxmox host. I used /root/migrate/work and that is reflected in the script.

In proxmox-convert-stage2.sh:

1. MIGRATE should be set to the Proxmox Template Path, usually /var/lib/vz/template/cache although if you want to put them on remote storage, here is where you can configure that
2. WORKBASE should be set to the path that you set in WORKBASE in the stage1 script. But keep in mind, it's a local path now.
3. FILES should be wherever you have deployed the files directory from this repository.

Migrate A Single Container

1. ssh OPENVZ_HOST
2. proxmox-convert-stage1.sh <VEID> # This may take awhile
3. vzctl stop <VEID>
4. proxmox-convert-stage1.sh <VEID> # This should be pretty quick
5. ssh PROXMOX_HOST
6. proxmox-convert-stage2.sh <VEID> # This may take awhile
7. Use the Proxmox web interface, or the CLI, to create a new LXC container based off of <VEID>.tar.xz. You may want to look at /etc/vz/conf/<VEID>.conf for the old container to get disk, cpu, ram, and network information. I took the opportunity to increase our minimum sizes a bit.
8. If you want to use your old SSH host keys, run this as root inside the new container: rm -f /etc/ssh/*_key /etc/ssh/*_key.pub; cp /root/ssh_keys/* /etc/ssh/

Migrate Multiple Containers

1. ssh OPENVZ_HOST
2. for veid in $(vzlist -a | sed -e 's/^ \+//' | cut -d ' ' -f 1 | tail -n +2) do proxmox-convert-stage1.sh $veid; done This will take a very long time, but you don't have to stop any containers to copy over the bulk of the files
3. For each container, plan some downtime, and start at step 3 under "Migrate a Single Container"

Issues

In some cases, my first 'yum update' after doing the migration changed some of the files that the stage2 script places in the new container. You can read through stage2 if you want, but here is where the files go if you want to use your ansible or puppet or whtever:

• files/lxc-halt -> /etc/init.d/lxc-halt
• files/lxc-sysinit.conf -> /etc/init/lxc-sysinit.conf
• files/power-status-changed.conf -> /etc/init/power-status-changed.conf
• files/securetty -> /etc/securetty
• files/tty.conf -> /etc/init/tty.conf

In particular, if you are unable to get the Proxmox Web Console to work, you need to replace /etc/securetty and /etc/init/tty.conf and then stop/start the container. The other files have to do with supporting clean shutdowns and reboots.

References

This whole thing is based on a bit of trial and error. But, I got a lot of good information from this page:

https://pve.proxmox.com/wiki/Convert_OpenVZ_to_LXC

Good Luck!