RHCSA (EX200) Exam Strategy: Time, Reboots and Lost Points

EX200 is a hands-on exam. You get one or two RHEL machines, around 150 minutes, and a list of tasks. Nobody marks your commands; a script checks the state of the machines after they have been rebooted. Keep that in mind for every task.

Before you start - Read the whole task list once and note dependencies. The root password reset usually comes first, because nothing else works without it. Networking comes next, because the repositories and the NFS server sit on the network. - Note the values (names, sizes, UIDs, ports) carefully. A user called natasha is not Natasha.

Time management - About 15–20 tasks in 150 minutes gives you roughly 7 minutes each. Do the quick wins first (users, cron, tuned, chrony), then storage, then SELinux and containers. - If a task resists for more than 10 minutes, write down where you got to and move on. Partial work in one task never costs you points in another, unless it breaks the boot. - Leave 15 minutes at the end for the reboot and a full check.

The verify-after-reboot habit - Firewall: always use --permanent and then firewall-cmd --reload. Afterwards, firewall-cmd --list-all should show your rule. - Services: systemctl enable --now, and check with systemctl is-enabled. - SELinux: /etc/selinux/config plus setenforce; semanage fcontext plus restorecon; setsebool -P. - Storage: put a UUID line in fstab, then systemctl daemon-reload, mount -a and findmnt --verify. A typo in fstab is the classic way to fail: the machine stops in emergency mode and the grader cannot reach anything. - Network: use nmcli connection profiles and nmcli con up. ip addr add is runtime only. - Do one deliberate reboot halfway through and another at the end. Then go through every task again: getenforce, df -h, swapon --show, systemctl is-active, curl, id user, crontab -l -u user.

Common ways to lose points - The root password reset without touch /.autorelabel, so root cannot log in once SELinux is enforcing. - XFS created where ext4 was asked for, or a size outside the allowed range. Check with lsblk and lvs. - An LV that was extended without its file system (lvextend without -r). - autofs maps written correctly while the service was never enabled. - A script that works in your shell but has no shebang or execute bit, or ignores the required exit status. - sudo rules written straight into /etc/sudoers with a syntax error. Use visudo -cf on a drop-in file. - Changing the Apache port or turning SELinux off "to make it work". The task says to fix labels and port types, and the grader checks for that.

Documentation is allowed. man pages, /usr/share/doc and --help all work in the exam. man 5 nfs, man semanage-fcontext (the examples section) and man systemd.timer are worth practising with now, so you know where to look under pressure.