Linux

Create, copy, move, rename, and remove files and directories safely.

Create and distinguish hard links and symbolic links.

Select filesystem objects using shell glob patterns and brace expansion.

Redirect standard input, standard output, and standard error without losing unintended data.

Connect commands with pipelines to transform command output.

Find matching text with grep and basic regular expressions.

Locate files by name, type, ownership, size, or modification time with find.

Create, inspect, extract, compress, and decompress tar archives with gzip and bzip2.

Log in as another account and switch users in a multi-user system.

Create, modify, lock, unlock, and delete local user accounts.

Set passwords and configure password-aging policies for local accounts.

Create and modify local groups and group memberships.

Delegate administrative commands safely through sudo configuration.

Set file ownership and standard user, group, and other permissions.

Control default file permissions with the shell umask.

Diagnose file-access failures caused by ownership, mode bits, ACLs, or missing directory traversal permission.

Configure and verify access to a DNF software repository.

Install, update, downgrade, and remove RPM packages with DNF.

Query package metadata, dependencies, installed files, and owning packages.

Configure a Flatpak remote and manage Flatpak applications.

Identify CPU-intensive and memory-intensive processes with ps, top, and related tools.

Control foreground and background jobs from an interactive shell.

Terminate or signal processes safely by PID, name, or job identifier.

Adjust process priority and select an appropriate system tuning profile.

Boot, reboot, shut down, and recover a Linux system using safe administrative commands.

Start, stop, restart, reload, and inspect services with systemctl.

Enable, disable, and mask systemd units persistently.

Switch systemd targets and configure the default boot target.

Modify persistent bootloader settings and temporary kernel arguments.

Interrupt the boot process to regain administrative access.

Locate and interpret service, kernel, authentication, and boot events with journalctl.

Configure persistent systemd journal storage and verify logs survive a reboot.

Identify disks, partitions, filesystems, UUIDs, labels, and mount relationships with Linux storage tools.

Create and delete GPT partitions without damaging unrelated data.

Create VFAT, ext4, and XFS filesystems on prepared block devices.

Mount and unmount local filesystems at runtime.

Configure reliable boot-time mounts by UUID or filesystem label in /etc/fstab.

Create, activate, deactivate, and persist swap space.

Add a partition, filesystem, or swap area to a running system non-destructively.

Diagnose and correct failed mounts and invalid /etc/fstab entries.

Create and remove LVM physical volumes on prepared storage.

Create, extend, reduce, and remove LVM volume groups.

Create, rename, and remove logical volumes.

Place a supported filesystem on a logical volume and mount it persistently.

Extend a logical volume and its filesystem without losing data.

Move or remove LVM storage while preserving required data.

Mount and unmount an NFS export manually.

Configure autofs to mount an NFS export on demand.

Interpret IPv4 and IPv6 addresses, prefixes, gateways, routes, and DNS settings.

Inspect active NetworkManager connections, interfaces, addresses, routes, and DNS configuration.

Configure a persistent static IPv4 connection with nmcli.

Configure a persistent IPv6 connection with nmcli.

Configure a system hostname and static hostname resolution.

Diagnose connectivity and name-resolution failures with ip, ping, ss, tracepath, dig, and curl.

Configure SSH key-based authentication and disable unsafe access methods where appropriate.

Transfer files securely with scp, sftp, and rsync over SSH.

Configure persistent firewalld zones, services, ports, and interface assignments.

Switch SELinux between enforcing and permissive modes and verify the active policy state.

List and interpret SELinux user, role, type, and level contexts for files and processes.

Restore default SELinux file contexts with restorecon.

Define and apply a persistent custom SELinux file-context mapping.

List, add, and remove SELinux network port labels.

Use SELinux Booleans to enable narrowly scoped service behavior.

Diagnose an SELinux denial with audit logs and apply a policy-supported correction.

Schedule and inspect a one-time task with at.

Create and validate recurring user and system cron jobs.

Create, enable, and inspect a systemd timer unit.

Create an executable Bash script with a correct interpreter directive and safe exit behavior.

Process positional parameters and validate required script inputs.

Capture and process command output inside a Bash script.

Conditionally execute shell commands with test expressions and if statements.

Process a sequence of files or arguments with a for loop.

Synchronize system time with an NTP service and verify clock status.

Deploy a basic HTTP service from a package and enable it at boot.

Troubleshoot an unavailable network service across process, socket, firewall, and SELinux layers.

Export a directory from an NFS server and verify client access.

Create and verify a restorable backup of system configuration and application data.

Restore selected data from a backup while preserving required ownership and permissions.

Configure log rotation for a locally managed service.

Assess CPU, memory, disk-space, inode, and load conditions during an incident.

Convert a written administration request into a safe, ordered implementation and validation checklist.

Repair a system that fails to boot because of an invalid persistent mount configuration.

Recover a failed systemd service by using its status, journal, unit definition, and dependencies.

Correct a persistent network configuration that prevents remote administration.

Resolve a service-access failure caused by an incorrect firewall or SELinux configuration.

Complete a timed RHCSA-style task set using only locally installed documentation.

Verify after reboot that users, storage, networking, services, schedules, firewall rules, and SELinux changes persist.

Create a concise portfolio runbook that documents a completed Linux administration project and its troubleshooting decisions.