RHCSA EX200 Cheat Sheet for RHEL 10: Commands and Quick Reference

Table of Contents

• Introduction
• User and Group Management
• File Permissions and Ownership
• Networking and Firewall
• Storage and Mounting
• Boot Process and Systemd
• Package Management (YUM/DNF)
• SELinux and Security
• Cron Jobs and Scheduling
• Conclusion

Introduction

The RHCSA EX200 exam is a hands-on, performance-based test that validates your Linux administration skills. This cheat sheet provides quick-access commands and core topics aligned with the Red Hat Certified System Administrator (RHCSA) objectives.

User and Group Management

• useradd username – Add new user
• passwd username – Set user password
• usermod -aG groupname username – Add user to a group
• groupadd groupname – Create new group
• id username – Show user's UID, GID, and groups
• chage -l username – List password aging info

File Permissions and Ownership

• chmod u+x file – Add execute to owner
• chown user:group file – Change ownership
• umask – Show default permission mask
• getfacl /path – View ACLs
• setfacl -m u:username:rwx /file – Modify ACL

Networking and Firewall

• nmcli dev status – Check network devices
• nmcli con up "connection-name" – Start connection
• ip addr – Show IP addresses
• firewall-cmd --add-service=http --permanent – Open firewall port
• firewall-cmd --reload – Reload firewall
• ss -tuln – List listening ports

Storage and Mounting

• lsblk – List block devices
• fdisk /dev/sdX – Partition disk
• mkfs.xfs /dev/sdX1 – Format partition
• mount /dev/sdX1 /mnt – Mount partition
• df -h – Show mounted disks
• vim /etc/fstab – Add persistent mount

Boot Process and Systemd

• systemctl status service – Show service status
• systemctl enable service – Enable service at boot
• journalctl -xe – View system logs
• grubby --default-kernel – View default boot kernel
• dracut -f – Rebuild initramfs

Package Management (YUM/DNF)

• dnf install package – Install package
• dnf remove package – Remove package
• dnf update – Update system
• dnf groupinstall "Server with GUI" – Install package group
• rpm -q package – Check if package is installed

SELinux and Security

• getenforce – Show SELinux status
• setenforce 0 – Set SELinux to permissive
• sestatus – Show SELinux mode
• semanage port -l – List SELinux port contexts
• restorecon -Rv /path – Restore SELinux contexts

Cron Jobs and Scheduling

• crontab -e – Edit user cron
• systemctl list-timers – View timers
• at now + 1 minute – Schedule one-time job
• systemctl start/stop timer – Manage systemd timers

Conclusion

This RHCSA cheat sheet is tailored for quick revision before your EX200 exam. While memorizing commands is helpful, practicing them in a real Linux environment like a home lab or training platform is critical. Combine this cheat sheet with hands-on tasks and you’ll be ready to ace the RHCSA certification in your first attempt.