# Upgrade Proxmox 8 to 9 Without Breaking Your Homelab

Upgrade Proxmox 8 to 9 safely. Includes real fixes for failed upgrades, apt errors, and GPU passthrough checks.

Author: Ruhani Rabin
Canonical: https://rabin.blog/upgrade-proxmox-8-to-9-without-breaking-your-homelab/
Published: 2026-04-12T15:49:31.000Z
Updated: 2026-10-15T00:00:00.000Z

**Let’s get one thing out of the way:**

> Proxmox upgrades are not fragile.\
> **People** are.

Most guides assume:

* nothing goes wrong
* you don’t interrupt anything
* you don’t get stuck in a pager
* you don’t panic halfway

**That’s not reality.**

This guide is based on an actual upgrade — including:

* interrupted upgrade
* broken package state
* lock issues
* recovery

If you follow this, you’ll finish the upgrade even if things go sideways.

## 🧭 What This Covers

* Proxmox VE 8 → 9
* No-subscription repo
* Single-node homelab (or small cluster)
* GPU passthrough setups (Plex, etc.)
* Recovery from broken upgrades

## ⚠️ Before You Start (Do Not Skip This)

### 1. Backup

If your backups are “probably fine”, they are not fine.

* Backup all VMs and containers
* Test restore if you’re serious

### 2. Upgrade to latest Proxmox 8 first

```bash
apt update
apt dist-upgrade
```

### 3. Run the upgrade checker

```bash
pve8to9 --full
```

You want:

* ❌ 0 failures
* ⚠️ warnings are acceptable

![Proxmox upgrade pre-check summary](https://rabin.blog/_astro/proxmox-upgrade-summary-passed-warnings.CCV7Qu0s_Z2wrevF.webp)

### 4. Disk space

```bash
df -h /
```

Minimum:

* 5GB usable
* **10GB preferred**

Here is an **_example_**:

```bash
root@pve2:~# df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/pve-root   94G   11G   79G  12% /
```

## 🛑 Stop Everything (Yes, Everything)

Before touching repositories:

### From UI:

Node → Bulk Actions → **Bulk Shutdown**

*This is not optional if you care about stability.*

![Bulk Shutdown option in Proxmox](https://rabin.blog/_astro/proxmox-bulk-shutdown-action-6df.BTOMQ_5O_Z4p0mX.webp)

### Why?

**Because during upgrade:**

* networking restarts
* services reload
* kernel changes

**Running VMs during this:**

* can hang
* can corrupt writes
* can behave unpredictably

You gain nothing by keeping them running.

## 🚀 Phase 1 — Switch Repositories

### 1. Switch Debian to Trixie

```bash
sed -i 's/bookworm/trixie/g' /etc/apt/sources.list
```

### 2. Remove old Proxmox repo

```bash
rm /etc/apt/sources.list.d/pve-install-repo.list
```

### 3. Add Proxmox 9 repo (no-subscription)

```bash
cat > /etc/apt/sources.list.d/proxmox.sources << EOF
Types: deb
URIs: http://download.proxmox.com/debian/pve
Suites: trixie
Components: pve-no-subscription
Signed-By: /usr/share/keyrings/proxmox-archive-keyring.gpg
EOF
```

### 4. Remove Ceph repo (if unused)

```bash
rm /etc/apt/sources.list.d/ceph.list 2>/dev/null
rm /etc/apt/sources.list.d/ceph.sources 2>/dev/null
```

Here is how it should go as an example:

```bash
root@pve2:~# sed -i 's/bookworm/trixie/g' /etc/apt/sources.list
root@pve2:~# rm /etc/apt/sources.list.d/pve-install-repo.list
root@pve2:~# cat > /etc/apt/sources.list.d/proxmox.sources << EOF
Types: deb
URIs: http://download.proxmox.com/debian/pve
Suites: trixie
Components: pve-no-subscription
Signed-By: /usr/share/keyrings/proxmox-archive-keyring.gpg
EOF
root@pve2:~# rm /etc/apt/sources.list.d/ceph.list 2>/dev/null
rm /etc/apt/sources.list.d/ceph.sources 2>/dev/null
root@pve2:~#
```

### 5. Update

```bash
apt update
```

### 6. Verify

```bash
apt policy
```

**You should NOT see:**

* ❌ bookworm

**You SHOULD see:**

* ✅ trixie
* ✅ pve-no-subscription

Example of the `apt policy` command:

```text
Package files:
 100 /var/lib/dpkg/status
     release a=now
 500 http://download.proxmox.com/debian/pve trixie/pve-no-subscription amd64 Packages
     release o=Proxmox,a=stable,n=trixie,l=Proxmox Debian Repository,c=pve-no-subscription,b=amd64
     origin download.proxmox.com
 500 https://deb.nodesource.com/node_22.x nodistro/main amd64 Packages
     release o=. nodistro,a=nodistro,n=nodistro,l=. nodistro,c=main,b=amd64
     origin deb.nodesource.com
 500 http://security.debian.org/debian-security trixie-security/main amd64 Packages
     release v=13,o=Debian,a=stable-security,n=trixie-security,l=Debian-Security,c=main,b=amd64
     origin security.debian.org
 500 http://deb.debian.org/debian trixie-updates/main amd64 Packages
     release v=13-updates,o=Debian,a=stable-updates,n=trixie-updates,l=Debian,c=main,b=amd64
     origin deb.debian.org
 500 http://deb.debian.org/debian trixie/contrib amd64 Packages
     release v=13.4,o=Debian,a=stable,n=trixie,l=Debian,c=contrib,b=amd64
     origin deb.debian.org
 500 http://deb.debian.org/debian trixie/main amd64 Packages
     release v=13.4,o=Debian,a=stable,n=trixie,l=Debian,c=main,b=amd64
     origin deb.debian.org
```

## 🔥 Phase 2 — The Upgrade

```bash
apt dist-upgrade
```

This process may show you additional screens. For example the below screen you can either `PG DN` multiple times, to go to the end or simply press **`q`**

![Linux terminal output about ping configuration.](https://rabin.blog/_astro/terminal-screen-system-updates-keyboard-prompt-888.D6yN6kmf_12U4Yj.webp)

### ⚠️ What Will Trip You Up

#### Pager screen

You’ll see: `lines xx-xx (END)`

Press: **`q`**

![Git update notes: git-daemon security changes.](https://rabin.blog/_astro/git-security-update-daemon-packages-removed-82f.C79zPtL8_1YagUT.webp)

#### Config prompts

`(Y/I/N/O/D/Z)`

If unsure: → press **Enter**

You may see other screens like this below, just keep the **`local version`** if you are not sure:

![Grub configuration options](https://rabin.blog/_astro/proxmox-grub-configuration-keep-local-version-835.i3FwKxW__ZusCLX.webp)

## 💥 If You Interrupt the Upgrade

### Recovery

```bash
ps aux | grep apt
kill -9 <PID>
dpkg --configure -a
apt -f install
apt dist-upgrade
```

Repeat until clean.

## ✅ Phase 3 — Finalization

### Check version

```bash
pveversion
```

This command **should output something like this below**, note the version number is `9.x.x`.

```bash
root@pve2:~# pveversion
pve-manager/9.1.7/16b139a017452f16 (running kernel: 6.8.12-20-pve)
```

### Reboot

```bash
reboot
```

Or you can just click on the UI.

![Reboot button in a Proxmox interface.](https://rabin.blog/_astro/proxmox-web-interface-reboot-button-d06.BS5gyL7n_ZGtpPx.webp)

> The reboot process will take some time. Once it is done, do not forget to force refresh your web access UI. (usually cmd+R or ctrl+R)

![Proxmox Virtual Environment console](https://rabin.blog/_astro/proxmox-virtual-environment-shell-access-abe.By8hPWuA_ZrgY24.webp)

### Confirm kernel

```bash
uname -r
```

## ⚠️ Important Change

`/etc/sysctl.conf` is no longer used

Move configs to: `/etc/sysctl.d/`

## 🔍 Post-Upgrade Checks

> You should only do this if any of your VM is running plex and uses NVidia card passthrough.

### GPU check

```bash
nvidia-smi
```

### NVENC check

```bash
ffmpeg -encoders | grep nvenc
```

### Real test

```bash
ffmpeg -f lavfi -i testsrc=duration=5:size=1280x720:rate=30 \
-c:v h264_nvenc -f null -
```

## 🧹 Cleanup

```bash
apt autoremove
apt modernize-sources
```

Example `apt autoremove`. Press **Y** to remove:

```bash
root@pve2:~# apt autoremove
REMOVING:
  libxenmisc4.17  proxmox-kernel-6.8.12-17-pve-signed


Summary:
  Upgrading: 0, Installing: 0, Removing: 2, Not Upgrading: 0
  Freed space: 579 MB


Continue? [Y/n] Y
```

Here is the example of `apt modernize-sources`. Press **Y** to continue.

```bash
root@pve2:~# apt modernize-sources


The following files need modernizing:
  - /etc/apt/sources.list
  - /etc/apt/sources.list.d/pve-enterprise.list
  - /etc/apt/sources.list.d/pvetest-for-beta.list


Modernizing will replace .list files with the new .sources format,
add Signed-By values where they can be determined automatically,
and save the old files into .list.bak files.


This command supports the 'signed-by' and 'trusted' options. If you
have specified other options inside [] brackets, please transfer them
manually to the output files; see sources.list(5) for a mapping.


For a simulation, respond N in the following prompt.
Rewrite 3 sources? [Y/n] Y


Modernizing /etc/apt/sources.list...
- Writing /etc/apt/sources.list.d/debian.sources


Modernizing /etc/apt/sources.list.d/pve-enterprise.list...


Modernizing /etc/apt/sources.list.d/pvetest-for-beta.list...
```

### 🤦‍♂️Gotcha - apt modernize-sources

> Be careful about the command `apt modernize-sources`, this will add back the **enterprise repo**, and that will start to give you **errors** when running `apt-get update` command.

![Proxmox apt-get update error 401 Unauthorized](https://rabin.blog/_astro/proxmox-update-error-401-unauthorized-91b.BCkgb5XG_ZnjL1u.webp)

**Now run these commands.**

```bash
rm /etc/apt/sources.list.d/pve-enterprise.sources
rm /etc/apt/sources.list.d/pve-enterprise.list 2>/dev/null
```

Now test the **`apt update`** command. And it should be as you see below, without errors.

```bash
root@pve2:~# apt update
Hit:1 http://security.debian.org/debian-security trixie-security InRelease
Hit:2 http://deb.debian.org/debian trixie InRelease
Hit:3 http://deb.debian.org/debian trixie-updates InRelease
Hit:4 https://deb.nodesource.com/node_22.x nodistro InRelease
Hit:5 http://download.proxmox.com/debian/pve trixie InRelease
All packages are up to date.
```

### 🤦‍♂️Gotcha - Proxmox NAG Screen is Back?

This can happen in some occasion. You will notice the nag screen about **`Proxmox does not have a subscription`** notice. In this case use this one liner script from **[Proxmox Post Install Community Script](https://community-scripts.org/scripts/post-pve-install)**. It is safe but as usual always inspect the source just to be sure.

Here is the one liner, **you must run this inside PVE Shell** (not inside a container).

```bash
bash -c "$(curl -fsSL https://raw.githubusercontent.com/community-scripts/ProxmoxVE/main/tools/pve/post-pve-install.sh)"
```

**Additional Instructions:**

> It is recommended to answer “yes” (y) to all options presented during the process. But use your best judgement as sometimes not all answer’s needs to be `Y`.

## 🧠 Final Thought

**You just need to follow the steps, be vigilant and it will be alright**. If your upgrade depends on luck instead of control, then you’re doing it wrong 😊.

## Related reading

* [Back up Proxmox configuration with Git](https://rabin.blog/proxmox-config-backup-git-version-control-pve-nodes/)
* [Fix Intel e1000e network hangs on Proxmox](https://rabin.blog/fix-intel-e1000e-detected-hardware-unit-hang-on-proxmox/)