How to install and configure Proxmox

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How to install and configure Proxmox

How-to written and screenshots taken on 2021 October 27 min read


What started as a project to run "some crypto applications" grew into something much bigger, but also more useful. I learned a tremendous amount about virtual machines, lxc containers and Proxmox. And although I'm just scratching the surface and I don't actually understand it, I know how to do some things. I'll write them down here, partly for myself, but also for you in hopes it will save one of us a lot of time and frustration.

Proxmox installation

Proxmox supplies an ISO file that installs Debian with Proxmox preinstalled and configured. This machine is known in Proxmox as a node.


If you install Proxmox using BIOS or UEFI mode the OS should be booted in the same mode as well. So do not change boot option in the BIOS after installation!

  1. Choose "Install Proxmox VE" in the boot screen (currently version 7.0)

  2. Accept the EULA

  3. Select the options and as filesystem choose zfs (RAID1). As the harddisks choose your two boot drives. If you have a hardware RAID card and configured your boot drives into a single logical drive, choose that one.

    Select Target Harddisk

  4. Set country, timezone and Keyboard Layout. You cannot choose "UTC" here, we'll correct that later

  5. Enter the root password

  6. Select the management NIC and set the address of the host (see host table above for hostname and IP address).

  7. Press the Install button and wait for installation to finish

  8. Reboot

  9. Press enter or wait for a few seconds to boot Proxmox from the boot loader

  10. You should now be able to enter the CLI with the password created during install (user: root)

  11. You should now also be able to enter the web interface at the address entered during installation, with the password created during install (user: root)

    Login to the Proxmox web interface

Official tutorial

The "official" tutorial, with all the images and a Youtube video on how to install and configure Proxmox can be found here:

Boot error

If you get an error during boot:

Command: /sbin/zpool import -N "rpool"
Message: cannot import 'rpool' : no such pool available
Error: 1
Failed to import pool 'rpool'.
Manually import the pool and exit.

You have to set a timeout of 20-30 seconds in grub. I can't remember how I did that, but at least here are the sources I could recover.



Proxmox has a lot of configuration options. Obviously many of them are dependent on what you want to achieve. I'll describe some of those in other posts. Here I'll focus on some basic, general configuration settings.

Always make backups

Proxmox config is very delicate. Almost all settings can be configured through the GUI, but sometimes you might have to dig into config files with the CLI. ALWAYS make a backup before doing so! I learned the hard way that messing up only one file (especially related to the cluster) can mean a full reinstall of that cluster!

Hide "no subscription" splash screen

No subscription splash screen

  1. Open a SSH shellsession to the Proxmox node.

  2. Browse to folder:

    cd /usr/share/javascript/proxmox-widget-toolkit
  3. Make a backup:

    cp proxmoxlib.js proxmoxlib.js.bak
  4. Open file with nano and edit:

    nano proxmoxlib.js
  5. Find the line (ctrl + w, enter No valid subscription, press enter):{
    title: gettext('No valid subscription'),
  6. Change line to:

    void({ //{
    title: gettext('No valid subscription'),
  7. Restart the Proxmox web service:

    systemctl restart pveproxy.service
  8. This needs to be repeated after every update of the proxmox-widget-toolkit. I.e. after every update of Proxmox. Or get a subscription of course.

Non-subscription repository

By default the subscription repository for Proxmox package updates is set. If you don't have a subscription (you don't need to) you can use the "no-subscription" repository.

  1. Browse to folder:

    cd /etc/apt/sources.list.d/
  2. Backup current file:

    mv pve-enterprise.list pve-enterprise.list.backup
  3. Create new files:

    echo "#deb bullseye pve-enterprise" > /etc/apt/sources.list.d/pve-enterprise.list
    echo "deb bullseye pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list
  4. Get update and install them:

    apt update
    apt dist-upgrade

It seems to be important to do apt dist-upgrade instead of apt upgrade. This does some things behind the scenes like some cleanup, not sure what exactly. Read my source for more:

Nested hypervisor

If you want to run nested hypervisors -a hypervisor in a VM-, you have to enable that. If your VM uses snap, this needs to be enabled.

  1. Check if nested hypervisor is enabled (kvm_intel for Intel CPU, kvm_amd for AMD)

    cat /sys/module/kvm_intel/parameters/nested
  2. If N, activate it. The first line is for Intel:

    echo "options kvm-intel nested=Y" > /etc/modprobe.d/kvm-intel.conf

    The second for AMD:

    echo "options kvm-amd nested=1" > /etc/modprobe.d/kvm-amd.conf
  3. Reboot or reload the kernel module (kvm_intel for Intel CPU, kvm_amd for AMD):

    modprobe -r kvm_intel
    modprobe kvm_intel
  4. check again:

    cat /sys/module/kvm_intel/parameters/nested

Set timezone

I want to have my servers run in UTC timezone.

  1. Run command and follow the GUI

    dpkg-reconfigure tzdata

Optional: Cluster setup

When you want to link multiple Proxmox nodes together it's called a cluster (shown as datacenter in the GUI). CLusters have a lot of quirks, I find, especially if you enabled 2FA and created users. You have to be logged in as root if I remember correctly. At least try it if something doesn't seem to work. When you have created a cluster, you can:

  • Use a single login
    • Single username-password
    • Single private-public key
  • Control the nodes, VM's and containers from a single GUI
  • Share configuration (files) between nodes
  • Migrate VM's and containers between nodes

So it's definitely worth your time and effort.

  1. Choose the master node and create a cluster through the GUI. Make sure the IP of the host machine is set correctly as you cannot change it later without having to recreate the whole cluster.

  2. Add the other nodes to the cluster by clicking the "Join Cluster" button.

That should be it, but in my experience it never works that easily. These are some things I encountered:

  • When you already have 2FA enabled, this will not work. You have to join the cluster through the command line:

    pvecm add IP-ADDRESS-MASTER-NODE -link0 LOCAL-IP-ADDRESS-LINK0 --use_ssh

    If you have setup multiple links, you have to specify them all. So use -link0, -link1 etc.

  • You cannot change the ip address through which the cluster communicates. Not on the master and not on the slave.

  • Never remove a node, reinstall and try to add it back with the same hostname/ip-address. You can add it back as a different node, but not as the same.

  • Also properly remove a node. If you don't no all changes are blocked because the cluster cannot reach consensus as the amount of "votes" are not as expected. I don't understand how all of this works, just trust me if your time is valuable.


That's it. You now have a basic Proxmox setup and can run your first virtual machines and LXC containers. In part 2 I'll explain how you link Proxmox to a NFS share for backups and how to mount external storage in general. For more articles on Proxmox, click the link.