CELE study guide
CELE · Work through your exam, one topic at a time.
The Certified Entry-Level Linux Professional (CELE) is an early-career credential for people who can already work at a Linux shell and want independent evidence of that skill. It suits career changers coming from help desk or Windows administration, students finishing a first Linux course, and junior staff who need a structured target before moving on to deeper administration certifications. The CELE study guide has 9 sections and about 3,237 words.
01Essential Linux concepts and architecture
This domain, Essential Linux concepts and architecture , tests whether you understand how a Linux system is assembled before you administer it: the kernel and user-space split, the boot chain, the filesystem hierarchy, and the service manager. Questions typically ask what happens at a given boot stage or which command reveals a kernel fact.
322 words, about 2 min02Installing and configuring Linux
This domain, Installing and configuring Linux , covers taking a machine from bare metal or a virtual disk to a bootable, configured host: disk layout, filesystems, persistent mounts, bootloader configuration, and post-install settings such as hostname, timezone, and the first administrative user. Partition tables: MBR (four primary partitions, extended/logical workaround) versus GPT (many partitions, required for UEFI boot with an EFI System Partition).
337 words, about 2 min03Filesystem navigation and file management
This domain, Filesystem navigation and file management , checks shell fluency as a file tool: moving through the hierarchy, locating files by attribute, copying and archiving safely, linking, and reading or filtering text streams. Navigation: pwd , cd , ls -la , absolute versus relative paths, .
353 words, about 2 min04Users, groups, and permissions
This domain, Users, groups, and permissions , tests account management and the permission model that decides who may read, write, or execute what, including special bits, umask, and ACLs. /etc/passwd holds name, UID, GID, GECOS, home, and shell; /etc/shadow holds the hash and aging data; /etc/group and /etc/gshadow define groups.
392 words, about 2 min05Processes, jobs, and system services
This domain, Processes, jobs, and system services , covers how programs become processes, how to inspect and signal them, how shell job control differs from persistent services, and how systemd supervises daemons. A process has a PID and a PPID; fork clones it and exec replaces the image.
389 words, about 2 min06Networking fundamentals and remote access
This domain, Networking fundamentals and remote access , tests addressing and routing basics, name resolution, troubleshooting tools, and secure remote administration over SSH. IPv4 addresses are 32-bit and CIDR notation gives the prefix length.
385 words, about 2 min07Package management and software installation
This domain, Package management and software installation , tests installing, removing, querying, and verifying software on both major package families, plus knowing when a source build is the right answer. Debian and Ubuntu: dpkg is the low-level tool and apt resolves dependencies.
359 words, about 2 min08Shell scripting and command-line utilities
This domain, Shell scripting and command-line utilities , tests writing small, correct scripts: quoting, exit status, tests, loops, functions, redirection, and making failures visible instead of silent. Start with #!/bin/bash , or #!/bin/sh for POSIX-only syntax.
337 words, about 2 min09Security basics and system administration tasks
This domain, Security basics and system administration tasks , tests day-to-day hardening and operations: least privilege, access control beyond mode bits, firewalling, patching, logging, and routine maintenance. Least privilege: run services as dedicated users, grant specific commands through sudo , and disable direct root SSH login.
363 words, about 2 min