Ubuntu LTS Upgrade

22 LTS to 24 LTS

sudo apt update
sudo apt upgrade -y
sudo apt full-upgrade -y
sudo apt autoremove --purge -y

cat /var/run/reboot-required 2>/dev/null && echo "Reboot needed" || echo "No reboot needed"

Reboot if needed:

sudo reboot

sudo apt install -y update-manager-core

grep ^Prompt /etc/update-manager/release-upgrades

Should be Prompt=lts. If not:

sudo sed -i 's/^Prompt=.*/Prompt=lts/' /etc/update-manager/release-upgrades

Disable unattended-upgrades:

sudo systemctl stop unattended-upgrades
sudo systemctl disable unattended-upgrades

Upgrade:

sudo DEBIAN_FRONTEND=noninteractive do-release-upgrade -f DistUpgradeViewNonInteractive

Reboot:

sudo reboot now

Should be 24.04 LTS:

lsb_release -a

24 LTS to 26

sudo apt update && sudo apt upgrade -y

sudo apt dist-upgrade -y

sudo apt autoremove -y

Check if LTS:

cat /etc/update-manager/release-upgrades

Should be Prompt=lts.

Allow additional SSH port:

iptables -I INPUT -p tcp --dport 1022 -j ACCEPT

Check main channel:

sudo do-release-upgrade -c

If found:

sudo do-release-upgrade -d

If not found, switch to development branch. Do it on your own risk.

sudo do-release-upgrade -d -c
sudo do-release-upgrade -d

sudo apt install -y update-manager-core

Drop additional SSH port:

iptables -A INPUT -p tcp --dport 1022 -j DROP

Enable unattended-upgrades:

sudo systemctl start unattended-upgrades
sudo systemctl enable unattended-upgrades