Post-Upgrade Checklist

# Confirm system version
lsb_release -a
cat /etc/os-release
 
# Confirm kernel version
uname -r
 
# Confirm architecture
uname -m
dpkg --print-architecture

# View boot time
uptime
systemd-analyze
 
# Check for errors during boot
systemd-analyze blame
journalctl -b -p err
 
# Check dmesg for errors
dmesg --level=err,warn | tail -30

# Check for broken packages
sudo dpkg --audit
 
# Fix broken dependencies
sudo apt --fix-broken install
 
# Complete any interrupted configuration
sudo dpkg --configure -a
 
# Check for held-back packages
apt list --upgradable

# Update package lists and install remaining updates
sudo apt update
sudo apt upgrade -y
sudo apt dist-upgrade -y

# Remove packages that are no longer needed
sudo apt autoremove --purge -y
 
# Clean package cache
sudo apt clean
 
# View installed old kernels
dpkg --list | grep linux-image | grep -v $(uname -r)
 
# Old kernels will be handled by autoremove; you can also remove them manually
# sudo apt purge linux-image-x.x.x-xx-generic

# Check for failed services
systemctl --failed
 
# If there are failed services, view details
# systemctl status failed-service-name
# journalctl -u failed-service-name
 
# View all running services
systemctl list-units --type=service --state=running

# If you saved the service list before upgrading
diff <(cat /backup/services-running-*.txt | awk '{print $1}' | sort) \
     <(systemctl list-units --type=service --state=running | awk '{print $1}' | sort)

# SSH
sudo systemctl status ssh
ssh localhost
 
# Web server
sudo systemctl status nginx 2>/dev/null || sudo systemctl status apache2 2>/dev/null
curl -I http://localhost
 
# Database
sudo systemctl status mysql 2>/dev/null || sudo systemctl status postgresql 2>/dev/null
 
# Docker
sudo systemctl status docker
docker ps
 
# Check all auto-start services
systemctl list-unit-files --state=enabled --type=service

# Check network interfaces
ip addr
 
# Check routing table
ip route
 
# Check DNS resolution
resolvectl status 2>/dev/null || cat /etc/resolv.conf
dig ubuntu.com +short
nslookup ubuntu.com
 
# Test external connectivity
ping -c 3 8.8.8.8
ping -c 3 ubuntu.com
 
# Check listening ports
ss -tlnp

# Check Netplan configuration
cat /etc/netplan/*.yaml
 
# Confirm network management tool
systemctl status systemd-networkd 2>/dev/null
systemctl status NetworkManager 2>/dev/null

# Check UFW status
sudo ufw status verbose
 
# Confirm rules are intact
sudo ufw status numbered

# Check disk space
df -h
 
# Check inode usage
df -i
 
# Check for filesystem errors
sudo dmesg | grep -i "ext4\|xfs\|btrfs" | grep -i error
 
# Check LVM status (if using LVM)
sudo lvs
sudo vgs
sudo pvs
 
# Check mount points
mount | column -t
cat /etc/fstab

# Confirm SSH configuration was not overwritten
sudo sshd -t
grep -E "^(PermitRootLogin|PasswordAuthentication|Port)" /etc/ssh/sshd_config
grep -rE "^(PermitRootLogin|PasswordAuthentication|Port)" /etc/ssh/sshd_config.d/
 
# Confirm custom SSH configuration is still in effect
sudo systemctl restart ssh

# Check user list
cat /etc/passwd | grep -v nologin | grep -v /bin/false
 
# Check sudo permissions
sudo cat /etc/sudoers.d/*
 
# Check SSH authorized keys
cat ~/.ssh/authorized_keys

# Check auto-update configuration
cat /etc/apt/apt.conf.d/20auto-upgrades
cat /etc/apt/apt.conf.d/50unattended-upgrades
 
# Ensure unattended-upgrades is running
sudo systemctl status unattended-upgrades

# Check web server configuration syntax
sudo nginx -t 2>/dev/null
sudo apache2ctl configtest 2>/dev/null
 
# Check PHP version and modules (if using PHP)
php -v
php -m
 
# Check SSL certificates
sudo certbot certificates 2>/dev/null

# Check Docker service
docker info
 
# Check running containers
docker ps
 
# Check stopped containers
docker ps -a --filter "status=exited"
 
# Restart Docker Compose projects
cd /path/to/project && docker compose up -d
docker compose ps

# MySQL/MariaDB
mysql -u root -p -e "SHOW DATABASES;"
mysql -u root -p -e "SELECT VERSION();"
 
# PostgreSQL
sudo -u postgres psql -c "SELECT version();"
sudo -u postgres psql -l

# Third-party sources disabled during the upgrade
ls /etc/apt/sources.list.d/*.distUpgrade 2>/dev/null
 
# View currently active sources
apt-cache policy | head -30
grep -r "^Types:" /etc/apt/sources.list.d/*.sources 2>/dev/null
grep -r "^deb " /etc/apt/sources.list.d/*.list 2>/dev/null

# Restore after confirming the source supports 26.04
# For example, restoring the Docker source
# sudo mv /etc/apt/sources.list.d/docker.list.distUpgrade /etc/apt/sources.list.d/docker.list
 
# Or re-add
# sudo add-apt-repository ppa:example/ppa
 
# Update sources
sudo apt update

# Check user cron
crontab -l
 
# Check system cron
cat /etc/crontab
ls /etc/cron.d/
ls /etc/cron.daily/
ls /etc/cron.weekly/
 
# Check systemd timers
systemctl list-timers --all

# Upgrade log directory
ls -la /var/log/dist-upgrade/
 
# View main log
cat /var/log/dist-upgrade/main.log | grep -E "(ERROR|WARNING)"
 
# View APT log
cat /var/log/dist-upgrade/apt.log | tail -50

# Clean old logs to free space
sudo journalctl --vacuum-time=7d
sudo journalctl --vacuum-size=500M

# Final confirmation
grep Prompt /etc/update-manager/release-upgrades
# Should output: Prompt=lts