#RHEL
62 posts
Red Hat Certified Engineer (RHCE) #13: System roles (rhel-system-roles)
The 13th post in the Red Hat Certified Engineer (RHCE) series. We cover how rhel-system-roles — a set of validated roles Red Hat ships — abstracts away RHCSA tasks. We walk through installation (dnf and ansible-galaxy collection), where the docs live (/usr/share/doc/rhel-system-roles) and the example-playbook copy pattern, the timesync/firewall/selinux/storage/network/postfix roles and their variables, and the exam regulars — automating NTP, firewall, and SELinux — with worked examples.
Red Hat Certified System Administrator (RHCSA) #10 Basic Networking: NetworkManager (nmcli), hostname, /etc/hosts
The tenth post in the Red Hat Certified System Administrator (RHCSA) series. We cover how NetworkManager manages networking on RHEL 9, how to create connections and set a static IP permanently with nmcli, how to change the hostname with hostnamectl and resolve names through /etc/hosts, and how to verify the result with the ip command — all typed out by hand. Setting a static IP so it survives a reboot is a perennial RHCSA exam task.
Red Hat Certified Engineer (RHCE) #12 Collection: Galaxy, Automation Hub
Part 12 of the Red Hat Certified Engineer (RHCE) series. We cover the concept of an Ansible collection and FQCN (namespace.collection.module), how to install collections and roles with ansible-galaxy, the way to install dependencies in bulk with requirements.yml, the difference between Galaxy and Automation Hub, and the collections_path setting in ansible.cfg — all from a hands-on exam point of view. We work through the exam staple of downloading a collection with requirements.yml and using it via FQCN as a worked example.
Red Hat Certified System Administrator (RHCSA) #9 System Operations: chronyd, journald, cron, systemd timer, tuned
The ninth post in the Red Hat Certified System Administrator (RHCSA) series. We set system time with timedatectl and chronyd, read and persist logs with journald and rsyslog, schedule jobs with cron and systemd timers, and tune system profiles with tuned — the operational tasks, organized around the commands you actually type on the exam.
Red Hat Certified Engineer (RHCE) #11: Writing and Using Roles
Part 11 of the Red Hat Certified Engineer (RHCE) series. We cover the standard role directory structure and ansible-galaxy role init, the difference between the roles key and include_role/import_role, why defaults sits at the lowest role variable precedence, and the dependencies in meta/main.yml plus roles_path. We practice the exam-favorite flow of writing a role and calling it from a playbook with worked examples.
Red Hat Certified System Administrator (RHCSA) #8 Packages and repositories: dnf, modules, AppStream
The eighth post in the Red Hat Certified System Administrator (RHCSA) series. We cover installing, removing, and searching packages with dnf, adding repositories, and working with AppStream module streams and profiles. From RHCSA staples like adding a specific repository and installing from it, all the way to switching module streams — all walked through with command examples.
Red Hat Certified Engineer (RHCE) #10 Ansible Vault: Managing Secrets
The tenth post in the Red Hat Certified Engineer (RHCE) series. We encrypt variable files with ansible-vault (create/edit/view/encrypt/decrypt/rekey), put secrets in group_vars/secret.yml and use them from a playbook, supply the password at runtime with --ask-vault-pass and --vault-password-file, and inline-encrypt a single variable with encrypt_string — all laid out command by command.
Red Hat Certified System Administrator (RHCSA) #7 File systems: XFS, ext4, mount/fstab, NFS, AutoFS
The seventh post in the Red Hat Certified System Administrator (RHCSA) series. We create file systems with mkfs.xfs and mkfs.ext4, handle mounts with mount/umount/findmnt, lock down persistent mounts that survive a reboot via UUID/LABEL and fstab, and finally type out NFS client mounts and AutoFS on-demand mounts by hand.
Red Hat Certified Engineer (RHCE) #9 Tags and conditionals: when, loop, until
The ninth post in the Red Hat Certified Engineer (RHCE) series. We organize the core tools that control the flow of a playbook — conditional execution with when, iteration with loop, retries with until, and partial runs with tags. We learn the exam-staple patterns hands-on: branching by OS, bulk-creating a user list, retrying while waiting for a service to come up, and using tags to run only the tasks you need.
Red Hat Certified System Administrator (RHCSA) #6: Local Storage 2 — LVM Expansion and LUKS Encryption
The sixth post in the Red Hat Certified System Administrator (RHCSA) series. We add a PV to a volume group and grow it with vgextend, enlarge the logical volume with lvextend, then extend the file system itself with xfs_growfs and resize2fs — and we build a LUKS-encrypted volume with cryptsetup, setting it up to unlock automatically at boot through crypttab and fstab. We also cover exam staples like XFS being impossible to shrink.
Red Hat Certified Engineer (RHCE) #8 Error handling: block/rescue/always, failed_when, ignore_errors
The eighth post of the Red Hat Certified Engineer (RHCE) series. We cover the error handling that controls the flow when a playbook fails mid-run. From the exam point of view, we work through structuring exceptions with block/rescue/always, letting failures slide with ignore_errors, defining your own failure conditions with failed_when, and shoring up the idempotency of the command module with changed_when.
Red Hat Certified System Administrator (RHCSA) #5: Local Storage 1 — Partitions, swap, LVM basics
The fifth post in the Red Hat Certified System Administrator (RHCSA) series. We check disks with lsblk and fdisk, create partitions with fdisk,parted, add swap with mkswap,swapon, build LVM with pvcreate,vgcreate,lvcreate, then mount it permanently with mkfs and fstab (UUID) — all typed out by hand. We carry RHCSA's most common task, "create an LVM and mount it," all the way through so it survives a reboot.