These are the Linux commands you use most when looking after a web server or VPS, grouped by task. They work on Ubuntu, Debian, AlmaLinux and Rocky Linux unless a note says otherwise; we checked them on Ubuntu 24.04, Debian 13 and AlmaLinux 9. Commands that change the system need sudo or the root user.
Moving around
pwd # where am I?
ls -la # list files, including hidden ones, with details
cd /var/www # go to a folder
cd .. # one level up
cd ~ # home folder
cd - # previous folderFiles and folders
mkdir -p backups/2026 # create folders (and parents)
cp -r site site-copy # copy a folder
mv old.txt new.txt # rename or move
rm file.txt # delete a file
rm -r old-folder # delete a folder and its contents
ln -s /var/www/app current # symbolic link
touch file.txt # create an empty file or update its timeGuides: rename files, remove folders, links.
Viewing and editing files
cat file.txt # print a short file
less /var/log/syslog # scroll a long file (q quits)
head -20 file.txt # first 20 lines
tail -f /var/log/nginx/error.log # follow a log live
nano /etc/hosts # simple editor (Ctrl+O save, Ctrl+X exit)Searching
find /var/www -name "wp-config.php" # files by name
find . -mtime -1 # changed in the last day
grep -rn "DB_NAME" /var/www/html # text inside files
which php # where a command livesPermissions and ownership
chmod 644 file.php # owner read/write, others read
chmod 755 script.sh # owner can run it
chown -R www-data:www-data /var/www/site # owner (apache on AlmaLinux)
ls -l # check permissionsUsers and passwords
whoami # current user
sudo adduser alice # Ubuntu, Debian (useradd -m alice on AlmaLinux)
sudo passwd alice # set a password
getent passwd # all accounts
id alice # user ID and groupsMore: change a user password.
Processes and services
top # live CPU and memory (htop is friendlier)
ps aux --sort=-%mem | head # biggest memory users
pgrep -a nginx # find a process
kill 1234 # stop process 1234
sudo systemctl status nginx # service status
sudo systemctl restart nginx # restart a service
sudo systemctl enable nginx # start at boot
journalctl -u nginx -n 50 # its recent log linesMore: list running processes.
Disk and memory
df -h # free space per disk
du -sh /var/www/* # size of each folder
du -h --max-depth=1 / -x | sort -rh | head # what fills the disk
free -h # memory and swap
uptime # load and time since bootNetwork
ip -4 addr # IP addresses
ss -ltnp # which programs listen on which ports
ping -c 4 example.com # is it reachable?
curl -I https://example.com # HTTP status and headers
dig +short example.com A # DNS lookup
nc -zv example.com 443 # is a port open?Packages
# Ubuntu, Debian
sudo apt update && sudo apt upgrade
sudo apt install nginx
apt list --installed
# AlmaLinux, Rocky Linux
sudo dnf upgrade
sudo dnf install nginx
dnf list installedArchives and transfers
tar -czf site.tar.gz site/ # create
tar -xzf site.tar.gz -C /restore # extract into a folder
zip -r site.zip site/ ; unzip site.zip -d /restore
scp -r site user@server:/var/www/ # copy over SSH
rsync -avz site/ user@server:/var/www/site/ # sync, only changes
wget -P /tmp https://example.com/file.tar.gz # downloadScheduling and system
crontab -l # your cron jobs
crontab -e # edit them
systemctl list-timers # systemd timers
cat /etc/os-release # distribution and version
hostnamectl # host name, OS and kernel
sudo reboot # restartMore: list cron jobs and read crontab syntax.
Tips that save time
- Press
Tabto complete names, and the up arrow (orCtrl+R) to find earlier commands. - Add
--helpto most commands, or read the manual withman command. - Before a risky change, copy the file:
cp nginx.conf nginx.conf.bak. - Use
tmuxfor long jobs, so they keep running if your SSH connection drops.
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