Proxmox 3.x to Proxmox 4.x

I have a very simple Proxmox setup at home. No cluster (anymore), but I did have to convert from 3.x to 4.x to keep current. This means going from OpenVZ to LXC. In reality they are very similar, but it's more or less like changing out the hood on the car (from a sysadmin perspective). The basic theory behind the conversion is not to upgrade the current machine in place, but to do a side-by-side or blue/green deployment in order to retain any information about the old guest VMs and containers as well as keep a back out plan. In my case, the easiest thing was to attach an NFS share to each host and backup from the old host and restore to the new host. After setting up the basic NFS share, the work is pretty simple. Backup restore. Backup, restore. Regular ol' virtual machines were done in a relatively short manner, but the OpenVZ containers weren't. These little guys backed up and restored quickly, but the setup on the new host is rather interesting. Here's the basic steps:
  1. After restore, give the newly created LXC container an ethernet adapter and IP address. Make sure that the subnet mask matches the LAN that this machine is on (e.g. /24 for the entire .1-254 subnet)
  2. SSH to the Proxmox host
  3. Enter the new LXC container from the Proxmox host:pct enter [Container ID]
  4. Ensure the locale is set (this was an issue I had with many Ubuntu containers):locale-gen "en_US.UTF-8" && dpkg-reconfigure locales
  5. Update the packages, and make sure to accept all: apt-get update && apt-get upgrade
If you've done all this, then everything *should* come back up properly. Before running the update I was unable to access the containers from ssh/web, but they would ping fine. After, all worked and worked as expected.
Share this