Update the APT Repositories

Proxmox VE 9 runs on Debian 13 (trixie) and uses the modern deb822 repository format (.sources files). Before upgrading, you must point both the Debian and Proxmox repositories at trixie.

Note

These are the same repository definitions the NDG PVE Post Install Script writes on Proxmox VE 9. You will re-run that script after the upgrade to reapply NDG configuration — but the repositories must be switched manually now so the upgrade can run.

Perform these steps from the host shell as root.

Debian base repositories

Write the Debian trixie sources to /etc/apt/sources.list.d/debian.sources:

cat > /etc/apt/sources.list.d/debian.sources <<'EOF'
Types: deb
URIs: http://deb.debian.org/debian
Suites: trixie trixie-updates
Components: main contrib
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg

Types: deb
URIs: http://security.debian.org/debian-security
Suites: trixie-security
Components: main contrib
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg
EOF

Empty the old one-line /etc/apt/sources.list so the bookworm entries are no longer used:

: > /etc/apt/sources.list

Proxmox VE no-subscription repository

Write the Proxmox VE trixie no-subscription source to /etc/apt/sources.list.d/proxmox.sources:

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

Remove the old bookworm no-subscription list if present:

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

Note

If you hold a Proxmox subscription, configure the pve-enterprise repository instead, per the official guide. NETLAB+ deployments typically use the no-subscription repository.

Disable the enterprise repository

Remove the enterprise .list file (if present from the install) so apt does not fail trying to reach it without a subscription:

rm -f /etc/apt/sources.list.d/pve-enterprise.list

Refresh the package index

Update the package lists and confirm there are no errors before continuing:

apt update

Tip

Proxmox also ships apt modernize-sources, which converts any remaining one-line .list files to the deb822 format automatically. You can run it and review the proposed changes.

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