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Portal | Level: L2: Operations | Topics: LPIC / LFCS Exam, Linux Fundamentals, Bash / Shell Scripting, systemd | Domain: Linux

LPIC / LFCS Exam Preparation — Primer

Why This Matters

The LPIC-1 (Linux Professional Institute) and LFCS (Linux Foundation Certified Sysadmin) are the Debian-family counterparts to RHCSA/RHCE. They are distro-neutral but lean heavily toward Debian/Ubuntu tooling. They validate core Linux administration skills that every ops engineer needs.

Certification Landscape

Cert Vendor Focus Distro Bias Exam Format
RHCSA (EX200) Red Hat RHEL sysadmin RHEL only Hands-on
RHCE (EX294) Red Hat Ansible automation RHEL only Hands-on
LPIC-1 (101+102) LPI General Linux admin Distro-neutral Multiple choice + fill-in
LPIC-2 (201+202) LPI Advanced admin Distro-neutral Multiple choice + fill-in
LFCS Linux Foundation Sysadmin Ubuntu or CentOS (choose) Hands-on
LFCE Linux Foundation Engineer Ubuntu or CentOS (choose) Hands-on

LFCS is the closest Debian-family equivalent to RHCSA — it's hands-on and lets you choose Ubuntu as your exam environment.

Timeline: LPI was founded in 1999, making LPIC-1 one of the oldest vendor-neutral Linux certifications. The Linux Foundation launched LFCS in 2014 as a hands-on alternative to LPIC's multiple-choice format, explicitly modeled on Red Hat's practical exam style.

LFCS Exam Domains

1. Essential Commands (25%)

# File operations
cp, mv, rm, mkdir, rmdir, touch, ln
find / -name "*.conf" -mtime -7
find / -type f -size +100M
locate filename    # uses updatedb database

# Archiving
tar czf archive.tar.gz /path/
tar xzf archive.tar.gz
tar tjf archive.tar.bz2    # list contents

# File permissions
chmod 755 script.sh
chmod u+x,g-w,o-r file
chown user:group file
chown -R user:group dir/

# Special permissions
chmod u+s binary     # setuid
chmod g+s directory  # setgid
chmod +t /tmp        # sticky bit

# ACLs
setfacl -m u:alice:rwx file
setfacl -m g:devs:rx directory
getfacl file
setfacl -x u:alice file     # remove
setfacl -b file              # remove all ACLs

# Text processing
grep -r "pattern" /path/
grep -E "regex|pattern" file
sed 's/old/new/g' file
sed -i 's/old/new/g' file   # in-place
awk '{print $1, $3}' file
cut -d: -f1 /etc/passwd
sort file | uniq -c | sort -rn
wc -l file
diff file1 file2
tee file                     # read stdin, write to stdout AND file

# I/O Redirection
command > file        # stdout to file (overwrite)
command >> file       # stdout to file (append)
command 2> file       # stderr to file
command &> file       # stdout + stderr to file
command1 | command2   # pipe stdout to next command
command < file        # stdin from file

Remember: Mnemonic for special permission bits: "Suid-Sgid-sTicky = SST = 4-2-1" — same pattern as rwx. setuid=4, setgid=2, sticky=1. So chmod 4755 means setuid + rwxr-xr-x.

2. Operation of Running Systems (20%)

# Process management
ps aux
ps -ef
top / htop
kill PID
kill -9 PID          # SIGKILL (force)
kill -HUP PID        # reload config
killall processname
pkill -f "pattern"
nice -n 10 command   # start with lower priority
renice -n 5 PID      # change priority

# systemd
systemctl start/stop/restart/reload service
systemctl enable/disable service
systemctl status service
systemctl list-units --type=service
systemctl list-unit-files --state=enabled
systemctl mask service      # prevent starting
systemctl unmask service
systemctl get-default       # current target
systemctl set-default multi-user.target
systemctl isolate rescue.target

# Journald
journalctl -u nginx
journalctl -u nginx --since "1 hour ago"
journalctl -p err            # priority: emerg, alert, crit, err, warning
journalctl -b                # current boot
journalctl -b -1             # previous boot
journalctl --disk-usage

# Boot process
# BIOS/UEFI → GRUB2 → kernel + initramfs → systemd → target

# GRUB2
cat /etc/default/grub
sudo update-grub             # Debian/Ubuntu
sudo grub2-mkconfig -o /boot/grub2/grub.cfg   # RHEL

# Scheduling
crontab -e                   # edit user crontab
crontab -l                   # list
sudo crontab -u alice -e     # edit another user's

# Cron format: min hour dom month dow command
# */5 * * * * /path/to/script.sh
# 0 2 * * 0 /weekly-backup.sh

at now + 5 minutes <<< "/path/to/script.sh"   # one-time job

3. User and Group Management (15%)

# Create/modify users
useradd -m -s /bin/bash -G sudo alice
useradd -r -s /sbin/nologin serviceuser   # system account
usermod -aG docker alice     # add to group
usermod -L alice             # lock account
usermod -U alice             # unlock account
userdel -r alice             # remove + home dir

# Passwords
passwd alice
chage -l alice               # password aging info
chage -M 90 alice            # max password age 90 days
chage -E 2025-12-31 alice    # account expiration

# Groups
groupadd developers
groupmod -n newname oldname
groupdel groupname
gpasswd -a alice developers  # add user to group
gpasswd -d alice developers  # remove user from group

# Files
/etc/passwd     # user accounts
/etc/shadow     # password hashes
/etc/group      # group memberships
/etc/gshadow    # group passwords
/etc/login.defs # login defaults
/etc/skel/      # skeleton for new home dirs

# PAM
/etc/pam.d/     # PAM configuration
/etc/security/limits.conf    # resource limits

# sudo
visudo                       # edit sudoers safely
/etc/sudoers.d/              # drop-in sudo rules
alice ALL=(ALL) NOPASSWD: ALL
%developers ALL=(ALL) /usr/bin/systemctl restart nginx

4. Networking (15%)

# Interface configuration
ip addr show
ip link show
ip route show
ip -s link show eth0    # statistics

# DNS
dig example.com
nslookup example.com
host example.com
cat /etc/resolv.conf
cat /etc/hosts
systemd-resolve --status    # or resolvectl

# Connectivity
ping host
traceroute host
mtr host                    # combined ping + traceroute
ss -tlnp                    # listening TCP sockets
ss -ulnp                    # listening UDP sockets
ss -s                       # socket statistics
curl -v http://example.com
wget http://example.com/file

# Network config (Ubuntu)
cat /etc/netplan/*.yaml
sudo netplan apply

# Network config (Debian)
cat /etc/network/interfaces
sudo ifup eth0
sudo ifdown eth0

# Hostname
hostnamectl set-hostname server01
hostname -f

# Firewall (Ubuntu)
sudo ufw status
sudo ufw allow 22/tcp
sudo ufw enable

# Firewall (raw iptables — exam may test this)
sudo iptables -L -n -v
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 443 -j ACCEPT
sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
sudo iptables -P INPUT DROP
sudo iptables-save > /etc/iptables/rules.v4

5. Storage Management (15%)

# Disk info
lsblk
fdisk -l
blkid
df -h
du -sh /path/

# Partitioning
sudo fdisk /dev/sdb          # MBR
sudo gdisk /dev/sdb          # GPT
sudo parted /dev/sdb

# Filesystems
sudo mkfs.ext4 /dev/sdb1
sudo mkfs.xfs /dev/sdb1
sudo tune2fs -l /dev/sdb1    # ext4 info
sudo xfs_info /dev/sdb1      # xfs info

# Mount
sudo mount /dev/sdb1 /mnt/data
sudo umount /mnt/data
cat /etc/fstab

# fstab entry
# /dev/sdb1  /mnt/data  ext4  defaults  0  2
# UUID=xxx   /mnt/data  xfs   defaults  0  0

# LVM
sudo pvcreate /dev/sdb
sudo vgcreate datavg /dev/sdb
sudo lvcreate -L 5G -n datalv datavg
sudo mkfs.ext4 /dev/datavg/datalv
sudo mount /dev/datavg/datalv /mnt/data

# Extend LVM
sudo lvextend -L +2G /dev/datavg/datalv
sudo resize2fs /dev/datavg/datalv     # ext4
sudo xfs_growfs /mnt/data             # xfs

# Swap
sudo mkswap /dev/sdb2
sudo swapon /dev/sdb2
sudo swapoff /dev/sdb2
free -h
cat /proc/swaps

# RAID (software)
sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc
cat /proc/mdstat
sudo mdadm --detail /dev/md0

6. Service Configuration (10%)

# SSH
/etc/ssh/sshd_config
PermitRootLogin no
PasswordAuthentication no
PubkeyAuthentication yes
sudo systemctl restart sshd

# DNS client
/etc/resolv.conf
/etc/hosts
/etc/nsswitch.conf

# NTP / time
timedatectl
timedatectl set-timezone America/New_York
sudo timedatectl set-ntp true    # enable chrony/systemd-timesyncd
chronyc sources -v

# HTTP (Apache on Debian)
sudo apt install apache2
sudo a2ensite mysite.conf
sudo a2enmod rewrite ssl
sudo a2dissite 000-default.conf
sudo systemctl reload apache2
# Config: /etc/apache2/sites-available/

# HTTP (Nginx on Debian)
sudo apt install nginx
sudo ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/
sudo nginx -t                    # test config
sudo systemctl reload nginx

# Logging
/var/log/syslog      # Debian
/var/log/messages    # RHEL
/var/log/auth.log    # Debian auth
/var/log/secure      # RHEL auth
/var/log/kern.log    # kernel
/var/log/dmesg       # boot messages

# rsyslog
/etc/rsyslog.conf
/etc/rsyslog.d/*.conf
# local6.* /var/log/myapp.log

# logrotate
/etc/logrotate.conf
/etc/logrotate.d/

LPIC-1 Additional Topics

LPIC-1 covers some topics LFCS doesn't emphasize:

Hardware and Boot

# Hardware info
lspci
lsusb
lscpu
lsblk
dmidecode
cat /proc/cpuinfo
cat /proc/meminfo

# Kernel modules
lsmod
modprobe module_name
modprobe -r module_name   # remove
modinfo module_name
/etc/modules-load.d/      # auto-load at boot

# Boot loader
update-grub               # Debian/Ubuntu
grub2-mkconfig            # RHEL
/etc/default/grub          # GRUB defaults

Shell Scripting (Tested on Both LPIC-1 and LFCS)

#!/bin/bash
set -euo pipefail

# Variables
NAME="world"
echo "Hello, $NAME"

# Conditionals
if [[ -f /etc/passwd ]]; then
  echo "File exists"
elif [[ -d /tmp ]]; then
  echo "Directory exists"
fi

# Loops
for host in web1 web2 web3; do
  ping -c 1 "$host" && echo "$host is up"
done

while read -r line; do
  echo "Line: $line"
done < /etc/hosts

# Functions
backup() {
  local src="$1"
  tar czf "${src##*/}-$(date +%Y%m%d).tar.gz" "$src"
}

# Exit codes
command_that_might_fail || {
  echo "Failed!" >&2
  exit 1
}

X Window / Desktop (LPIC-1 Only)

# Display manager
systemctl status gdm          # GNOME
systemctl status lightdm      # Ubuntu/Xfce
systemctl status sddm         # KDE

# X forwarding
ssh -X user@remote
export DISPLAY=:0

# Wayland check
echo $XDG_SESSION_TYPE        # x11 or wayland

Exam Tips

LFCS (Hands-On)

  1. Choose Ubuntu if you're more comfortable with Debian-family
  2. Know vim basics — you will need to edit files
  3. Practice with systemd — it's on every modern distro
  4. Know both iptables AND ufw — exam may test either
  5. Time management: 2 hours, ~25 tasks. Don't get stuck
  6. man pages are available — use them
  7. Verify your work after each task

LPIC-1 (Multiple Choice + Fill-In)

  1. Memorize exact command flags — fill-in-the-blank requires precision
  2. Know both Debian AND RHEL tools — the exam is distro-neutral
  3. Study the weight of each topic — focus on high-weight areas
  4. Use practice exams — the question format matters
  5. Two exams required: 101-500 AND 102-500

Interview tip: Both LFCS and LPIC-1 are respected but serve different purposes on a resume. LFCS proves you can do the work (hands-on). LPIC-1 proves you know the theory (multiple choice). If you can only take one, LFCS is more credible for operations roles because the exam format matches the job.

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Prerequisites

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