Preventing Auto-Upgrades in Jetpack 6.x

JetPack 6.x uses three layers for updates: APT Timers, Periodic Configs, and Snapd. The system configuration shell script for the NRU series can be found here. Please download and execute this script on your device.

1. Disable APT Systemd Timers

These are the primary background triggers for apt update and apt upgrade.

sudo systemctl stop apt-daily.timer
sudo systemctl stop apt-daily-upgrade.timer
sudo systemctl disable apt-daily.timer
sudo systemctl disable apt-daily-upgrade.timer
sudo systemctl mask apt-daily.service
sudo systemctl mask apt-daily-upgrade.service

Note: mask ensures the services cannot be started by other processes.

2. Disable Periodic APT Configurations

Even if the timers are off, APT's internal logic may trigger updates. Edit or create the config file:

sudo nano /etc/apt/apt.conf.d/10periodic

Set all values to "0":

APT::Periodic::Enable "0";
APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "0";

3. Disable Snapd Service (Recommended)

Snap packages (like VSCode or Firefox) update independently of APT. If you don't need Snap, removing it is the safest way to prevent background bandwidth spikes:

sudo systemctl stop snapd.service
sudo systemctl disable snapd.service
sudo systemctl mask snapd.service
sudo systemctl mask snapd.socket
sudo systemctl mask snapd.seeded.service

4. Lock NVIDIA L4T Packages

Because the NRU series utilizes a custom carrier board, you must prevent the system from updating native Jetson Linux (L4T) packages. Updating these packages via standard NVIDIA repositories may overwrite custom device trees or drivers required by the NRU hardware, leading to boot failure or peripheral malfunction.

dpkg -l | grep nvidia-l4t | awk '{print $2}' | xargs sudo apt-mark hold

5. Verification

After a reboot, run this command to ensure no update timers are active:

sudo systemctl list-timers | grep apt

Expected Result: No output or showing the timers as masked / inactive.