LCA Certified Linux Administrator Exam — Questions and Answers

Question 1: Which command would you use to restore a specific file 'etc/passwd' from a tar archive 'backup.tar.gz'?

tar -rzf backup.tar.gz etc/passwd
tar -tzf backup.tar.gz etc/passwd
tar -xzf backup.tar.gz etc/passwd (Correct answer)
tar -czf backup.tar.gz etc/passwd

Correct answer: tar -xzf backup.tar.gz etc/passwd

tar -xzf extracts (-x) from a gzip-compressed (-z) archive file (-f), and specifying 'etc/passwd' restores only that file.

Question 2: Which file contains the persistent mount information in Linux?

/etc/disktab
/etc/mount.conf
/etc/fstab (Correct answer)
/etc/mtab

Correct answer: /etc/fstab

The `/etc/fstab` file stores persistent mount information, meaning it defines file systems that should be mounted automatically every time the system boots. Each entry in this file specifies a device, its mount point, file system type, and various options. This ensures that critical partitions and devices are always available.

Question 3: In the context of LCA certification, what is the most important consideration when implementing web server & database administration?

Minimizing documentation to save time
Ensuring alignment with established standards, stakeholder needs, and best practices (Correct answer)
Delegating all responsibilities to junior staff
Completing implementation as quickly as possible regardless of quality

Correct answer: Ensuring alignment with established standards, stakeholder needs, and best practices

When implementing web server & database administration, LCA professionals must ensure alignment with industry standards and stakeholder needs. Hasty implementation without proper planning often leads to compliance issues and suboptimal outcomes.

Question 4: Which command lists all cron jobs configured for a specific user named 'webadmin'?

crontab -u webadmin -l (Correct answer)
crontab --user webadmin --list
cat /etc/cron.d/webadmin
crontab -l webadmin

Correct answer: crontab -u webadmin -l

crontab -u <username> -l lists the crontab entries for the specified user; this requires root or sudo privileges to view another user's crontab.

Question 5: What does 'mkswap /dev/sdf1' followed by 'swapon /dev/sdf1' accomplish?

Encrypts the partition and uses it as swap
Formats and activates a swap partition for virtual memory use (Correct answer)
Formats sdf1 as ext4 and mounts it as /swap
Creates a swap file on sdf1

Correct answer: Formats and activates a swap partition for virtual memory use

mkswap writes the swap signature to the partition, and swapon enables it for immediate use as virtual memory.

Question 6: What is the effect of the Apache directive 'Options -Indexes' in a Directory block?

Prevents Apache from generating directory listings when no index file exists (Correct answer)
Disables all mod_rewrite rules
Blocks access to hidden files
Removes execute permissions from CGI scripts

Correct answer: Prevents Apache from generating directory listings when no index file exists

Options -Indexes prevents Apache from generating a directory listing, returning a 403 Forbidden instead when no index file is found.

Question 7: Which command tests whether TCP port 80 on host 203.0.113.5 is open without using nmap?

nc -zv 203.0.113.5 80 (Correct answer)
ping -p 80 203.0.113.5
curl -v telnet://203.0.113.5:80
traceroute -p 80 203.0.113.5

Correct answer: nc -zv 203.0.113.5 80

'nc -zv host port' attempts a TCP connection without sending data (-z) and reports the result verbosely (-v).

Question 8: A sysadmin needs to add a second disk to an existing LVM volume group. Which sequence is correct?

fdisk → lvextend → vgextend
vgcreate → pvcreate → lvextend
vgextend → pvcreate → lvextend
pvcreate → vgextend → lvextend (Correct answer)

Correct answer: pvcreate → vgextend → lvextend

You must first initialize the disk as a physical volume (pvcreate), then add it to the volume group (vgextend), then optionally extend logical volumes (lvextend).

Question 9: Which command shows the logs of a container running in a Kubernetes pod named 'webserver'?

kubectl describe pod webserver
kubectl logs pod/webserver (Correct answer)
kubectl get events --pod=webserver
kubectl exec webserver -- journalctl

Correct answer: kubectl logs pod/webserver

'kubectl logs pod/webserver' streams the stdout/stderr of the container running in the specified pod.

Question 10: What is the effect of running 'chmod 4755' on an executable?

Removes all special permission bits
Sets the SUID bit so the file runs with the owner's privileges (Correct answer)
Sets the SGID bit so the file runs with group privileges
Sets the sticky bit and makes it world-writable

Correct answer: Sets the SUID bit so the file runs with the owner's privileges

The leading '4' in octal notation sets the Set-UID bit, causing execution under the file owner's UID.

Question 11: What does the 'x' in the password field of /etc/passwd indicate?

The account is disabled
The account has no password
The password uses MD5 hashing
The password is stored in /etc/shadow (Correct answer)

Correct answer: The password is stored in /etc/shadow

An 'x' in the password field of /etc/passwd means the actual hashed password is stored in the shadowed /etc/shadow file.

Question 12: How should LCA professionals handle confidential information related to web server & database administration?

Share freely with all colleagues for transparency
Delete all records after project completion
Follow established protocols for data protection, access control, and disclosure in accordance with applicable regulations (Correct answer)
Store information without any security measures

Correct answer: Follow established protocols for data protection, access control, and disclosure in accordance with applicable regulations

Confidential information must be handled according to established protocols, regulatory requirements, and professional ethics standards, including proper access control and disclosure procedures.

Question 13: What does 'bare metal recovery' refer to in disaster recovery?

Recovering only user data files without reinstalling the OS
Restoring a complete system to new or wiped hardware with no prior OS installed (Correct answer)
Restoring virtual machine snapshots
Recovering from a RAID failure

Correct answer: Restoring a complete system to new or wiped hardware with no prior OS installed

Bare metal recovery restores an entire system image (OS, applications, and data) onto hardware that has no existing operating system.

Question 14: Which configuration directive in /etc/resolv.conf allows the resolver to try multiple domain suffixes when resolving a short hostname?

nameserver
search (Correct answer)
options ndots
domain

Correct answer: search

The 'search' directive specifies a list of domain suffixes appended when a hostname without dots is queried.

Question 15: Which of the following best describes a key competency required for virtualization & container management in LCA practice?

The ability to work independently without any oversight
Strong analytical skills combined with effective communication and ethical judgment (Correct answer)
Memorization of all relevant regulations without understanding context
Reliance on a single methodology for all situations

Correct answer: Strong analytical skills combined with effective communication and ethical judgment

LCA professionals working in virtualization & container management need analytical skills to assess situations, communication skills to convey findings, and ethical judgment to make sound decisions.

Question 16: Which construct in bash is used to perform pattern matching in a case statement?

match $VAR with pattern -> ...
if $VAR == pattern; then ...
switch $VAR { pattern: ... }
case $VAR in pattern) ... ;; esac (Correct answer)

Correct answer: case $VAR in pattern) ... ;; esac

The `case ... esac` construct uses glob patterns to match values and execute corresponding code blocks.

Question 17: You observe high retransmission rates in 'ss -s' output. What does this most likely indicate?

The firewall is blocking UDP traffic
The DNS server is unreachable
The MTU is set too low for the interface
Network congestion or packet loss causing TCP to resend unacknowledged segments (Correct answer)

Correct answer: Network congestion or packet loss causing TCP to resend unacknowledged segments

TCP retransmissions occur when acknowledgments are not received in time, typically due to packet loss or congestion.

Question 18: In SELinux, what does the Boolean 'httpd_can_network_connect' control?

Whether the httpd process can initiate outbound network connections (Correct answer)
Whether Apache can bind to privileged ports
Whether SELinux enforces labels on Apache config files
Whether Apache can read NFS-mounted directories

Correct answer: Whether the httpd process can initiate outbound network connections

This Boolean allows or denies the Apache httpd daemon from making outbound TCP connections, useful for reverse-proxy scenarios.

Question 19: A differential backup strategy is used. Sunday is a full backup; Tuesday's differential is corrupt. Which backups are needed to restore to Wednesday?

Wednesday differential only
Sunday full + all incrementals Mon-Wed
Sunday full + Tuesday differential + Wednesday differential
Sunday full + Wednesday differential (Correct answer)

Correct answer: Sunday full + Wednesday differential

Differential backups always include all changes since the last full backup, so Wednesday's differential plus Sunday's full backup is sufficient regardless of Tuesday.

Question 20: Which command displays the UUID of a block device?

fdisk -l
lsblk -f
blkid (Correct answer)
df -h

Correct answer: blkid

blkid queries block device attributes including UUID, filesystem type, and label.

Question 21: Which feature of LVM is commonly used to enable consistent online backups of a running system?

LVM mirroring
LVM thin provisioning
LVM snapshots (Correct answer)
LVM striping

Correct answer: LVM snapshots

LVM snapshots create a point-in-time copy of a logical volume that can be backed up while the source volume remains online and in use.

Question 22: What does the 'noatime' mount option do?

Disables updating access timestamps on reads (Correct answer)
Prevents file creation timestamps from being set
Removes modification times from files
Stops journaling of time metadata

Correct answer: Disables updating access timestamps on reads

The 'noatime' option prevents the kernel from updating the access time (atime) on every file read, reducing disk write overhead.

Question 23: When a LCA professional encounters an unfamiliar challenge in performance monitoring & tuning, what is the recommended first course of action?

Proceed based on personal intuition alone
Postpone addressing the issue indefinitely
Apply the solution used for the most recent similar problem without adaptation
Research applicable standards, consult with subject matter experts, and document the approach (Correct answer)

Correct answer: Research applicable standards, consult with subject matter experts, and document the approach

Professional practice requires a methodical approach to unfamiliar challenges: research the applicable standards, consult experts when needed, and document the reasoning for the chosen approach.

Question 24: Which file controls which services are started at boot in a systemd system?

/etc/init.d/
/etc/services
/etc/rc.local
/etc/systemd/system/default.target.wants/ (Correct answer)

Correct answer: /etc/systemd/system/default.target.wants/

Symlinks in /etc/systemd/system/default.target.wants/ (or similar .wants directories) define which units are enabled to start at the default target.

Question 25: A system fails to boot after editing /etc/fstab. Which rescue mode command removes a bad entry without a GUI?

mount --repair /etc/fstab
fsck /etc/fstab
fdisk /etc/fstab
vi /etc/fstab after mounting root read-write (Correct answer)

Correct answer: vi /etc/fstab after mounting root read-write

In rescue mode, remounting the root filesystem read-write with 'mount -o remount,rw /' then editing /etc/fstab with vi corrects bad entries.

Question 26: Which Bacula daemon runs on the backup client and is responsible for reading/writing data on the client system?

bacula-mon (Monitor)
bacula-fd (File Daemon) (Correct answer)
bacula-dir (Director)
bacula-sd (Storage Daemon)

Correct answer: bacula-fd (File Daemon)

The Bacula File Daemon (bacula-fd) runs on each client and handles local file I/O during backup and restore operations.

Question 27: Which Linux installation method allows installation over the network?

PXE Boot Network installation (Correct answer)
USB stick installation.
Live CD installation.
Dual boot installation.

Correct answer: PXE Boot Network installation

PXE (Preboot eXecution Environment) Boot Network installation is a method that allows a computer to boot and install an operating system over a network without needing local storage or an optical drive. This is particularly useful for deploying Linux to multiple machines efficiently in a corporate or data center environment. It centralizes the installation process and reduces manual effort.

Question 28: What is the purpose of Apache's mod_proxy_fcgi module?

Proxies WebSocket connections to backend servers
Caches FastCGI responses on disk
Forwards requests to FastCGI backends such as PHP-FPM (Correct answer)
Provides load balancing across multiple Apache instances

Correct answer: Forwards requests to FastCGI backends such as PHP-FPM

mod_proxy_fcgi allows Apache to forward requests to FastCGI applications (like PHP-FPM) using the FastCGI protocol.

Question 29: What does 'restorecon -Rv /var/www/html' do?

Reloads the SELinux policy from /etc/selinux
Restores SELinux file contexts based on policy for the directory tree (Correct answer)
Changes all files to the httpd_sys_content_t context regardless of policy
Recursively removes SELinux contexts from the directory

Correct answer: Restores SELinux file contexts based on policy for the directory tree

restorecon applies the correct SELinux contexts as defined in the policy database, -R for recursive, -v for verbose.

Question 30: How should LCA professionals handle confidential information related to network configuration & troubleshooting?

Share freely with all colleagues for transparency
Follow established protocols for data protection, access control, and disclosure in accordance with applicable regulations (Correct answer)
Delete all records after project completion
Store information without any security measures

Correct answer: Follow established protocols for data protection, access control, and disclosure in accordance with applicable regulations

Confidential information must be handled according to established protocols, regulatory requirements, and professional ethics standards, including proper access control and disclosure procedures.

Question 31: Which Nginx directive defines a named location block for internal redirects only?

location #name {}
location ~name {}
location internal /name {}
location @name {} (Correct answer)

Correct answer: location @name {}

A named location prefixed with @ (e.g., location @fallback) is only accessible via internal Nginx directives like try_files or error_page, not directly by clients.

Question 32: A file has permissions -rwsr-xr-x. What does the 's' in the owner execute position indicate?

SGID bit is set
The file is a symbolic link
Sticky bit is set
SUID bit is set (Correct answer)

Correct answer: SUID bit is set

An 's' replacing the owner execute bit means the SUID bit is set, causing the file to run as its owner.

Question 33: When a LCA professional encounters an unfamiliar challenge in web server & database administration, what is the recommended first course of action?

Proceed based on personal intuition alone
Postpone addressing the issue indefinitely
Apply the solution used for the most recent similar problem without adaptation
Research applicable standards, consult with subject matter experts, and document the approach (Correct answer)

Correct answer: Research applicable standards, consult with subject matter experts, and document the approach

Professional practice requires a methodical approach to unfamiliar challenges: research the applicable standards, consult experts when needed, and document the reasoning for the chosen approach.

Question 34: Which bootloader configuration file must be updated after adding a new kernel in a GRUB 2 system?

/etc/grub.conf
/etc/default/grub
/boot/grub2/grub.cfg (Correct answer)
/boot/grub/grub.cfg

Correct answer: /boot/grub2/grub.cfg

On GRUB 2 systems, /boot/grub2/grub.cfg is the active config file, but it should be regenerated with grub2-mkconfig rather than edited directly.

Question 35: A host has two NICs: eth0 (192.168.1.10/24) and eth1 (10.0.0.5/24). Traffic to 10.0.0.0/24 is unexpectedly using eth0. What is the most likely cause?

A more specific route for 10.0.0.0/24 is missing, so the default route via eth0 is used (Correct answer)
The NIC driver is outdated
IPv6 is interfering with IPv4 routing
The firewall is redirecting packets

Correct answer: A more specific route for 10.0.0.0/24 is missing, so the default route via eth0 is used

Without a specific route for 10.0.0.0/24 via eth1, the kernel falls back to the default route, which exits through eth0.

Question 36: What is the 3-2-1 backup rule?

3 servers, 2 SANs, 1 cloud provider
3 full backups, 2 incremental, 1 differential per week
3 copies of data, on 2 different media types, with 1 offsite copy (Correct answer)
3 daily backups, 2 weekly, 1 monthly

Correct answer: 3 copies of data, on 2 different media types, with 1 offsite copy

The 3-2-1 rule is a best practice: keep 3 total copies of data, stored on 2 different media types, with at least 1 copy stored offsite.

Question 37: What is the purpose of 'dracut' on Red Hat-based systems?

Manages systemd unit files
Installs kernel modules
Generates the initramfs image (Correct answer)
Configures GRUB bootloader entries

Correct answer: Generates the initramfs image

dracut is the tool used on Red Hat/Fedora systems to build the initramfs (initial RAM filesystem) image that the bootloader passes to the kernel.

Question 38: Which fail2ban component reads log files and triggers bans based on defined filters?

fail2ban-server (Correct answer)
fail2ban-client
jail.conf
filter.d

Correct answer: fail2ban-server

fail2ban-server is the daemon that monitors logs and communicates with the firewall to block offending IPs.

Question 39: What is the most effective way to measure success in package management & software installation within LCA professional practice?

Rely solely on supervisor opinion
Use a combination of quantitative metrics, qualitative assessments, and stakeholder feedback aligned with defined objectives (Correct answer)
Compare only with industry averages without considering context
Count only the number of activities completed

Correct answer: Use a combination of quantitative metrics, qualitative assessments, and stakeholder feedback aligned with defined objectives

Effective measurement combines multiple data sources — quantitative metrics, qualitative assessments, and stakeholder feedback — all aligned with clearly defined objectives for a comprehensive evaluation.

Question 40: Which LVM command extends a logical volume AND resizes its ext4 filesystem in one step?

lvextend -r -L +10G /dev/vg0/lv0 (Correct answer)
lvextend -L +10G /dev/vg0/lv0
lvresize /dev/vg0/lv0
vgextend vg0 /dev/sdb

Correct answer: lvextend -r -L +10G /dev/vg0/lv0

The -r flag with lvextend calls resize2fs automatically after extending the logical volume, handling both the LV and filesystem resize in one command.

Question 41: Which log file should an administrator check first to view SELinux AVC denial messages?

/var/log/audit/audit.log (Correct answer)
/var/log/selinux.log
/var/log/messages
/var/log/secure

Correct answer: /var/log/audit/audit.log

The auditd daemon writes AVC (Access Vector Cache) denial records to /var/log/audit/audit.log.

Question 42: What octal permission value sets read+write for owner, read-only for group, and no permissions for others?

644
620
660
640 (Correct answer)

Correct answer: 640

640 = owner rw- (6), group r-- (4), others --- (0).

Question 43: In Nginx, which block directive defines a group of backend servers for load balancing?

backend
server
proxy_pass
upstream (Correct answer)

Correct answer: upstream

The upstream block in Nginx defines a group of servers that can be referenced by proxy_pass for load balancing.

Question 44: Which bootloader is most commonly installed with Linux systems?

GRUB (Correct answer)
NTLDR
LILO
Syslinux

Correct answer: GRUB

GRUB (GRand Unified Bootloader) is the most commonly installed bootloader with modern Linux systems. Its primary function is to load the operating system kernel into memory and pass control to it, allowing the system to start up. GRUB supports multiple operating systems and offers a flexible configuration for booting various kernels or even other operating systems installed on the same machine.

Question 45: What is the purpose of the /etc/hosts.deny file in TCP Wrappers?

Denies access to specified hosts for wrapped services (Correct answer)
Configures iptables blacklist rules
Sets kernel network security parameters
Lists services exempt from firewall rules

Correct answer: Denies access to specified hosts for wrapped services

TCP Wrappers checks /etc/hosts.allow first, then /etc/hosts.deny to determine whether to permit a connection.

Question 46: Which partition table format supports disks larger than 2TB and more than 4 primary partitions?

MBR
GPT (Correct answer)
APM
BSD disklabel

Correct answer: GPT

GUID Partition Table (GPT) supports disks over 2TB and allows up to 128 partitions by default, overcoming MBR's limitations.

Question 47: What does 'apt-get install --no-install-recommends' do differently from a standard install?

Installs without asking for confirmation
Installs only required dependencies, skipping recommended packages (Correct answer)
Skips optional and suggested packages only
Installs recommended packages instead of required ones

Correct answer: Installs only required dependencies, skipping recommended packages

The --no-install-recommends flag tells apt to install only mandatory dependencies, not the 'Recommends' listed by the package.

Question 48: What command runs a shell script named 'myscript.sh'?

start myscript.sh
execute myscript.sh
run myscript.sh
sh myscript.sh (Correct answer)

Correct answer: sh myscript.sh

To run a shell script named `myscript.sh`, you can explicitly invoke the shell interpreter, such as `sh` (for Bourne shell compatible scripts) or `bash` (for Bash scripts), followed by the script's filename. This tells the system to execute the script using the specified shell. Alternatively, if the script has execute permissions and a shebang line, you can run it directly with `./myscript.sh`.

Question 49: What is the role of 'createrepo' command on RPM-based systems?

Creates a new empty RPM repository
Creates an RPM spec file
Downloads RPMs to create a local repo
Creates repository metadata from a directory of RPM files (Correct answer)

Correct answer: Creates repository metadata from a directory of RPM files

createrepo generates the repodata/ directory with XML metadata that makes a directory of RPMs usable as a YUM/DNF repository.

Question 50: What command permanently adds HTTP service to the active firewalld zone?

firewall-cmd --permanent --add-service=http (Correct answer)
firewall-cmd --add-service=http
firewall-cmd --reload --add-service=http
firewall-cmd --zone=public --add-service=http

Correct answer: firewall-cmd --permanent --add-service=http

The --permanent flag ensures the rule persists across reboots; --reload is then needed to apply it.

Question 51: A directory has the sticky bit set (drwxrwxrwt). What restriction does this impose?

Files inherit the directory's group
Only root can delete files in it
Users can only delete files they own (Correct answer)
No new files can be created in it

Correct answer: Users can only delete files they own

The sticky bit on a directory prevents users from deleting or renaming files owned by others, even with write access.

Question 52: Which iptables target silently drops packets without sending any response?

BLOCK
REJECT
DENY
DROP (Correct answer)

Correct answer: DROP

DROP silently discards the packet, whereas REJECT sends an ICMP error back to the sender.

Question 53: Which kernel parameter passed at boot disables SELinux for a single session?

enforcing=0
security=none
selinux=permissive
selinux=0 (Correct answer)

Correct answer: selinux=0

Passing selinux=0 on the kernel command line completely disables SELinux for that boot session without permanently changing the policy configuration.

Question 54: In the context of LCA certification, what is the most important consideration when implementing user & permission management?

Minimizing documentation to save time
Completing implementation as quickly as possible regardless of quality
Ensuring alignment with established standards, stakeholder needs, and best practices (Correct answer)
Delegating all responsibilities to junior staff

Correct answer: Ensuring alignment with established standards, stakeholder needs, and best practices

When implementing user & permission management, LCA professionals must ensure alignment with industry standards and stakeholder needs. Hasty implementation without proper planning often leads to compliance issues and suboptimal outcomes.

Question 55: Which command is used to check the status of the firewall on a Linux system?

ufw status
systemctl firewall status
iptables --status
firewalld-cmd --state (Correct answer)

Correct answer: firewalld-cmd --state

For systems using `firewalld`, the `firewall-cmd --state` command is used to check if the `firewalld` service is running. It will output "running" if the firewall daemon is active, or indicate if it's not. This is the standard way to quickly ascertain the operational status of `firewalld`.

Question 56: What does the command 'newgrp developers' accomplish?

Renames the current group to developers
Creates a new group named developers
Adds the current user to the developers group permanently
Starts a subshell with developers as the effective primary group (Correct answer)

Correct answer: Starts a subshell with developers as the effective primary group

newgrp opens a new shell session where the specified group becomes the user's effective primary group for that session.

Question 57: Which of the following best describes a key competency required for backup & disaster recovery in LCA practice?

Strong analytical skills combined with effective communication and ethical judgment (Correct answer)
Reliance on a single methodology for all situations
The ability to work independently without any oversight
Memorization of all relevant regulations without understanding context

Correct answer: Strong analytical skills combined with effective communication and ethical judgment

LCA professionals working in backup & disaster recovery need analytical skills to assess situations, communication skills to convey findings, and ethical judgment to make sound decisions.

Question 58: In bash, what is a here-document used for?

Providing multi-line input to a command inline in the script (Correct answer)
Importing another script
Defining a function
Creating a temporary file automatically

Correct answer: Providing multi-line input to a command inline in the script

A here-document (`<< DELIMITER ... DELIMITER`) feeds multiple lines of text directly as stdin to a command without needing a separate file.

Question 59: Which command saves a Docker image to a tar archive file?

docker commit
docker save (Correct answer)
docker dump
docker export

Correct answer: docker save

'docker save' exports an image (including all layers and metadata) to a tar file for offline transfer.

Question 60: Which command adds an existing physical volume /dev/sde to volume group 'vg_data'?

pvextend vg_data /dev/sde
vgadd /dev/sde vg_data
lvextend vg_data /dev/sde
vgextend vg_data /dev/sde (Correct answer)

Correct answer: vgextend vg_data /dev/sde

vgextend adds one or more initialized PVs to an existing volume group, increasing its total capacity.

LCA Certified Linux Administrator Exam

The LCA Certified Linux Administrator certification validates the fundamental skills required to administer Linux systems, including installation, configuration, and basic troubleshooting.

Questions

90 min

Time Limit

70%

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