LFCS Cheat Sheet

#	Domain	Weight	Questions	Practice
1.0	Essential Commands	20%	138	Practice →
4.0	Networking	25%	166	Practice →
5.0	Service Configuration	12%	84	Practice →
6.0	Storage Management	20%	124	Practice →
Total	77%	720

Domain

Weight

Questions

Practice

1.0

Essential Commands

20%

138

Practice →

4.0

Networking

25%

166

Practice →

5.0

Service Configuration

12%

Practice →

6.0

Storage Management

20%

124

Practice →

Total

77%

720

Domain Quick Reference

1.0Essential Commands

Candidates must navigate files, edit text, manage processes, set permissions, mount storage, and configure networking using tools like ls, grep, systemctl, chmod, mount, and ip. The critical thing is correct syntax and paths, since every command runs live and errors cost points.

20%

Key concepts

✓Navigating and manipulating files with ls, cp, mv, rm, find and tar
✓Searching and editing text using grep, sed, awk and vi
✓Managing processes and jobs with ps, top, kill, systemctl
✓Handling permissions, ownership, links and basic storage with chmod, chown, mount

Watch out for

⚠Using rm -rf or redirection carelessly and destroying data or config files needed by later exam tasks.
⚠Forgetting that chmod symbolic modes and umask interact, so new files get unexpected permissions.
⚠Editing with sed -i without a backup, then being unable to recover the original file contents.

4.0Networking

Configure and troubleshoot interfaces with ip, nmcli, and netplan, manage routes, DNS via /etc/resolv.conf, and firewalld or ufw rules. Get the persistent config right: changes must survive reboot, not just apply at runtime.

25%

Key concepts

✓Configure static IPv4/IPv6 addresses and routes using ip, nmcli, or Netplan
✓Manage hostname resolution via /etc/hosts, /etc/resolv.conf, and systemd-resolved
✓Control inbound traffic with firewalld zones, firewall-cmd, or ufw rules
✓Inspect listening sockets and connections using ss, netstat, and lsof

Watch out for

⚠Editing /etc/resolv.conf directly on systemd-resolved systems, where changes are overwritten and should instead go through resolvectl or Netplan
⚠Forgetting to make firewalld rules permanent with --permanent and reload, so they vanish after reboot or reload
⚠Using ifconfig and route from net-tools instead of the ip command, which is the expected modern toolset

5.0Service Configuration

Start, enable, mask, and troubleshoot units with systemctl, configure hostname and DNS via hostnamectl and /etc/resolv.conf, and set up services like sshd, httpd, and chronyd. The critical skill is diagnosing failed units with systemctl status and journalctl.

12%

Key concepts

✓Starting, stopping, enabling, and masking systemd units with systemctl and journalctl
✓Configuring persistent network settings, hostname, and name resolution on Linux
✓Setting up and securing SSH server access, keys, and sshd_config options
✓Deploying services like Apache httpd, NFS exports, or chrony time sync

Watch out for

⚠Running systemctl start without enable, so the service does not survive a reboot during grading
⚠Editing sshd_config or exports without reloading or restarting the daemon, leaving changes inactive
⚠Using runtime-only ip or hostname commands instead of persistent config files, so settings vanish after reboot

6.0Storage Management

Candidates must partition disks with fdisk/parted, create ext4/XFS/swap with mkfs, mount via /etc/fstab, and build LVM/RAID with pvcreate/vgcreate/lvcreate/mdadm. The critical thing: use UUIDs in fstab, not device names, to survive reboots.

20%

Key concepts

✓Partitioning disks with fdisk, gdisk, and parted using GPT or MBR labels
✓Creating and tuning ext4, XFS, and swap filesystems with mkfs and mkswap
✓Mounting by UUID in /etc/fstab and verifying with findmnt and mount -a
✓Building LVM volume groups and logical volumes with pvcreate, vgcreate, lvcreate

Watch out for

⚠Writing /etc/fstab entries with device names like /dev/sdb1 instead of UUIDs, which break when disk ordering changes after reboot
⚠Forgetting to run mkfs before mounting a new partition, or mounting the whole disk instead of its partition
⚠Resizing a filesystem without resizing the underlying LVM logical volume first, leaving unusable space or corrupting data

Exam Day Reminders

→Read every question stem fully — look for qualifiers like 'MOST likely,' 'BEST,' or 'EXCEPT.'

→Flag uncertain questions and come back — don't waste time on one question.

→Eliminate obviously wrong options first, then choose between remaining ones.

→Trust your first instinct unless you have a specific reason to change.

→For LFCS, scenarios typically have one clearly best answer — look for the option that matches the specific constraints in the question.

#	Domain	Weight	Questions	Practice
1.0	Essential Commands	20%	138	Practice →
4.0	Networking	25%	166	Practice →
5.0	Service Configuration	12%	84	Practice →
6.0	Storage Management	20%	124	Practice →
Total	77%	720

Domain

Weight

Questions

Practice

1.0

Essential Commands

20%

138

Practice →

4.0

Networking

25%

166

Practice →

5.0

Service Configuration

12%

Practice →

6.0

Storage Management

20%

124

Practice →

Total

77%

720

Domain Quick Reference

1.0Essential Commands

20%

Key concepts

✓Navigating and manipulating files with ls, cp, mv, rm, find and tar
✓Searching and editing text using grep, sed, awk and vi
✓Managing processes and jobs with ps, top, kill, systemctl
✓Handling permissions, ownership, links and basic storage with chmod, chown, mount

Watch out for

⚠Using rm -rf or redirection carelessly and destroying data or config files needed by later exam tasks.
⚠Forgetting that chmod symbolic modes and umask interact, so new files get unexpected permissions.
⚠Editing with sed -i without a backup, then being unable to recover the original file contents.

4.0Networking

25%

Key concepts

✓Configure static IPv4/IPv6 addresses and routes using ip, nmcli, or Netplan
✓Manage hostname resolution via /etc/hosts, /etc/resolv.conf, and systemd-resolved
✓Control inbound traffic with firewalld zones, firewall-cmd, or ufw rules
✓Inspect listening sockets and connections using ss, netstat, and lsof

Watch out for

⚠Editing /etc/resolv.conf directly on systemd-resolved systems, where changes are overwritten and should instead go through resolvectl or Netplan
⚠Forgetting to make firewalld rules permanent with --permanent and reload, so they vanish after reboot or reload
⚠Using ifconfig and route from net-tools instead of the ip command, which is the expected modern toolset

5.0Service Configuration

12%

Key concepts

✓Starting, stopping, enabling, and masking systemd units with systemctl and journalctl
✓Configuring persistent network settings, hostname, and name resolution on Linux
✓Setting up and securing SSH server access, keys, and sshd_config options
✓Deploying services like Apache httpd, NFS exports, or chrony time sync

Watch out for

⚠Running systemctl start without enable, so the service does not survive a reboot during grading
⚠Editing sshd_config or exports without reloading or restarting the daemon, leaving changes inactive
⚠Using runtime-only ip or hostname commands instead of persistent config files, so settings vanish after reboot

6.0Storage Management

20%

Key concepts

✓Partitioning disks with fdisk, gdisk, and parted using GPT or MBR labels
✓Creating and tuning ext4, XFS, and swap filesystems with mkfs and mkswap
✓Mounting by UUID in /etc/fstab and verifying with findmnt and mount -a
✓Building LVM volume groups and logical volumes with pvcreate, vgcreate, lvcreate

Watch out for

⚠Writing /etc/fstab entries with device names like /dev/sdb1 instead of UUIDs, which break when disk ordering changes after reboot
⚠Forgetting to run mkfs before mounting a new partition, or mounting the whole disk instead of its partition
⚠Resizing a filesystem without resizing the underlying LVM logical volume first, leaving unusable space or corrupting data

Exam Day Reminders

→Read every question stem fully — look for qualifiers like 'MOST likely,' 'BEST,' or 'EXCEPT.'

→Flag uncertain questions and come back — don't waste time on one question.

→Eliminate obviously wrong options first, then choose between remaining ones.

→Trust your first instinct unless you have a specific reason to change.

→For LFCS, scenarios typically have one clearly best answer — look for the option that matches the specific constraints in the question.

LFCS Exam Blueprint — At a Glance

Domain Quick Reference

1.0Essential Commands

4.0Networking

5.0Service Configuration

6.0Storage Management

Exam Day Reminders

More LFCS resources

LFCS Cheat Sheet

LFCS Exam Blueprint — At a Glance

Domain Quick Reference

1.0Essential Commands

4.0Networking

5.0Service Configuration

6.0Storage Management

Exam Day Reminders

More LFCS resources