How to Upgrade Proxmox VE 7 to Version 8

In the video below, we show you how to upgrade Proxmox VE from version 7 to 8

Proxmox recently announced the release of of Proxmox VE version 8

And that follows on from the release of Debian version 12, which Proxmox VE uses as its operating system

But a major upgrade like this has to be done from the command line

Useful links:
https://pve.proxmox.com/wiki/Upgrade_from_7_to_8

Update Proxmox VE
The first thing we need to do is to make sure Proxmox VE is up to date as far as version 7 is concerned

As far as I’m aware we don’t have a maintenance mode for Proxmox VE

So, if you have a standalone server then shutdown any virtual machines that are running and make sure you don’t have any that will start at boot

If you have a cluster you could also migrate your virtual machines to another server

Now if you’re using High Availability, you’ll also want to make sure virtual machines won’t be automatically migrated back to this one

This will makes things less disruptive as we’ll be probably restarting the server twice to upgrade it to verion 8

Next, we need to make sure that Debian and Proxmox VE are fully up to date

Navigate to the server, then to Updates and click Refresh

If any updates are found, click Upgrade

This opens a shell and you’ll be prompted to agree to the upgrades

You can also do this from the shell, or an SSH session

apt update
apt dist-upgrade -y

Once this has been completed, reboot the server

In the GUI click Reboot, or from the command line run the following command

reboot now

Once the server is back up, open the shell or connect to it using SSH and run the following command

pve7to8 --full

This was added fairly recently and allows you to check for potential problems if you upgrade the server from version 7 to 8

Assuming no issues are found we’ll check to see what version we’re running

pveversion

At the time of recording, this should be 7.4-16

This is useful because the GUI only tells you the version of the server you’ve logged into

Upgrade Proxmox VE
Now because we are doing a major upgrade of the server, as a precaution you’ll want to make sure that you’ll be able to get console access to it if things go wrong

You could run the upgrade from the console, but an SSH session makes it easier to copy and paste the correct commands

If something goes wrong, however, we may only be able to access the server via the console, so it makes sense to check that’s possible before proceeding

To upgrade Proxmox VE and Debian, we need to update the repository information

Debian 11 is known as Bullseye whilst Debian 12 is Bookworm

First we need to update the sources.list file

Whilst you could edit this with a text editor like nano and make changes with Ctrl-h, instead we’ll use the stream editor command

sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list

This basically replaces all instances of bullseye in /etc/apt/sources.list with bookworm

The -i parameter is to overwrite the contents of the file, otherwise we would just have the result output to the screen

The s/bullseye/bookworm/g part is an instruction to match the regular-expression bullseye and replace it with bookworm, and to do this for all instances hence the g flag

The /etc/apt/sources.list.d folder can contain files about other repositories so it should be checked for other files to update

ls -l /etc/apt/sources.list.d

The Enterprise subscription for instance will likely be a file called pve-enterprise.list

sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list.d/pve-enterprise.list

For Ceph, expect to find a ceph.list file

sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list.d/ceph.list

We then update the repository cache again, but this time it will based on Bookworm

apt update

Now we can upgrade to Debian 12 and Proxmox VE 8

apt dist-upgrade

The upgrade will pause with information

You can read through this or press q to quit and continue the upgrade

After that, questions may arise about changes to be made

Expect to be asked if you want to be prompted for for every service that needs to restart. Typically you won’t

After that you will get various questions to see if you want to replace an existing configuration file

Some examples are as follows:

For /etc/issue you can answer with the default N as we’re told Proxmox VE autogenerates this on boot

For /etc/ssh/sshd_config there was a change which deprecates ChallengeResponseAuthentication in favour of KbdInteractiveAuthentication. Even if you have made changes to this file, it would be better to replace the current version with the maintainer’s version and then update that one to suit your own purposes later, for example, to restrict authentation to SSH keys only

For /etc/lvm/lvm.conf it would be best to opt for the maintainer’s version we’re told

If prompted for /etc/default/grub it would be best to keep the current version as the assumption is you must have changed this and those changes need to remain

For /etc/apt/sources.list.d/pve-enterprise.list it would be best to opt for the maintainer’s version

But if you’re ever in doubt, stick eith the file you have

Once done reboot the server for the changes to take effect

reboot now

Post Update
Assuming the server comes back up it should now be on version 8 which we can check from a shell or SSH session

pveversion

If you have a cluster, it makes sense to check this for each computer you upgrade, as the GUI only tells you the version of the server you’ve logged into through the web browser

For Lab users that are only using the non-subscription updates, you will have to disable the enterprise updates again if you opted to replace the file

Navigate to Updates | Repositories, select pve-enterprise entry then click Disable

Subscription notifications will also need disabling again if you don’t want these

For a cluster, you’ll have to repeat the same upgrade process for every other node

While a cluster may be able to opreate in the interim with servers running different versions, the best practice is to have all servers running the same version

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