2025-02-05
Linux servers are the backbone of modern IT infrastructure, powering everything from web applications to cloud services. Mastering Linux server administration is essential for DevOps engineers, system administrators, and IT professionals. This guide provides practical, verified commands and techniques to help you manage Linux servers effectively.
Essential Linux Server Commands
1. System Information
To check system information, use the following command:
uname -a
This displays the kernel version, hostname, and other system details.
2. Disk Usage
Monitor disk usage with:
df -h
The `-h` flag makes the output human-readable.
3. Memory Usage
Check memory usage using:
free -m
This shows memory usage in megabytes.
4. Process Management
List running processes:
top
To kill a process, use:
kill <PID>
Replace `` with the process ID.
5. Network Configuration
View network interfaces:
ip addr show
To restart the network service:
systemctl restart networking
6. User Management
Add a new user:
sudo adduser <username>
Grant sudo privileges:
sudo usermod -aG sudo <username>
7. File Permissions
Change file permissions:
chmod 755 <filename>
Modify ownership:
chown <user>:<group> <filename>
8. Package Management
Update package lists:
sudo apt update
Install a package:
sudo apt install <package-name>
9. Firewall Configuration
Allow a port through the firewall:
sudo ufw allow <port>
Enable the firewall:
sudo ufw enable
10. Log Monitoring
View system logs:
sudo journalctl -xe
Tail log files in real-time:
tail -f /var/log/syslog
What Undercode Say
Linux server administration is a critical skill for IT professionals, and mastering it requires hands-on practice with commands and tools. Here are some additional tips and commands to enhance your Linux server management skills:
- Automate Tasks with Cron Jobs
Edit the crontab file:
crontab -e
Add a cron job to schedule tasks:
* * * * * /path/to/script.sh
- Secure SSH Access
Disable root login:
sudo nano /etc/ssh/sshd_config
Change `PermitRootLogin` to `no`. Restart the SSH service:
sudo systemctl restart sshd
- Backup and Restore
Create a backup using `tar`:
tar -czvf backup.tar.gz /path/to/directory
Restore from a backup:
tar -xzvf backup.tar.gz -C /path/to/restore
- Monitor System Performance
Use `htop` for an interactive process viewer:
sudo apt install htop htop
- Network Troubleshooting
Test connectivity with `ping`:
ping google.com
Trace the route to a destination:
traceroute google.com
- File System Checks
Check and repair the file system:
sudo fsck /dev/sdX
Replace `/dev/sdX` with the appropriate device.
- Kernel Updates
List installed kernels:
dpkg --list | grep linux-image
Remove old kernels:
sudo apt remove linux-image-<version>
- Service Management
Start a service:
sudo systemctl start <service-name>
Enable a service to start on boot:
sudo systemctl enable <service-name>
- Disk Partitioning
List disk partitions:
sudo fdisk -l
Create a new partition:
sudo fdisk /dev/sdX
- Environment Variables
Set an environment variable:
export VAR_NAME="value"
Make it persistent by adding it to `.bashrc`:
echo 'export VAR_NAME="value"' >> ~/.bashrc
For further reading, check out these resources:
By practicing these commands and techniques, you’ll become proficient in managing Linux servers, ensuring optimal performance and security for your IT infrastructure.
References:
Hackers Feeds, Undercode AI
