LPIC-1 Practice Test 2 — 25 Questions

Question 1

Which command adds a new group named 'developers' to the system?

Accepted Answer

groupadd developers. The correct command to add a new group on a Linux system is `groupadd developers`. This command creates a new group entry in the system's group database (typically /etc/group). The `groupadd` utility is the standard tool for this task in Linux, and it is part of the shadow-utils package.

Answer

addgroup developers

Answer

newgroup developers

Answer

groupadd -r developers

Question 2

A system reports 'No space left on device' but 'df -h' shows only 60% usage. Which command would help identify the cause?

Accepted Answer

df -i. The 'No space left on device' error can also occur when the filesystem runs out of inodes, even if disk space is not full. The command 'df -i' shows inode usage; if inodes are exhausted, no new files can be created, causing the error. 'lsof +L1' lists deleted open files, which consume disk blocks but not inodes, so it is not the right tool when disk space is only 60% used.

Answer

stat /

Answer

lsof +L1

Answer

du -sh /

Question 3

Which THREE statements are true about the sed command?

Accepted Answer

sed -i 's/foo/bar/g' file.txt replaces all occurrences of foo with bar in the file.. The `-i` flag in sed enables in-place editing, directly modifying the file rather than just outputting changes to stdout. The substitution command `'s/foo/bar/g'` replaces all occurrences of `foo` with `bar` globally on each line, and with `-i`, the changes are written back to the file.

Answer

sed 's/old/new/g' file.txt permanently changes the file.

Answer

sed uses extended regular expressions by default.

Question 4

A system administrator is troubleshooting a server where the /var partition is full, causing services to fail. The administrator deletes old log files in /var/log, but the available space does not increase. Which step should be taken next?

Accepted Answer

Use 'lsof /var/log' to find processes holding deleted file handles, then restart those processes.. When a file is deleted while a process still holds an open file descriptor to it, the file's data blocks are not freed until that process releases the handle. The `lsof /var/log` command identifies such processes, and restarting them forces the kernel to release the deleted inodes, thereby reclaiming the disk space. This is why option C is the correct next step.

Answer

Run 'sync; echo 3 > /proc/sys/vm/drop_caches' to clear cache.

Answer

Remount the /var partition with the 'noatime' option.

Answer

Run 'df -i' to check inode usage.

Question 5

A systems administrator maintains a Linux web server running Apache HTTP Server (version 2.4) with three virtual hosts. The server logs are stored in /var/log/httpd/ and are rotated using logrotate, which is configured with the default settings that came with the Apache package. The administrator has noticed that after the nightly log rotation, the main access log file (access_log) is empty, while the rotated log files (e.g., access_log.1, access_log.2) contain the previous day's data. Furthermore, new HTTP requests are being logged into the most recent rotated file (access_log.1) instead of the current access_log file. The administrator has verified that the logrotate cron job runs successfully, and that the log files are owned by the root user with read/write permissions for the root group. No errors appear in the system logs. The Apache service continues to run and serve web pages. Which of the following actions should the administrator take to ensure that Apache writes new log entries to the current access_log file after rotation?

Accepted Answer

Add a postrotate script to the logrotate configuration that sends a USR1 or HUP signal to the Apache process to cause it to reopen the log files.. The issue is that after logrotate moves the current access_log to access_log.1, Apache continues writing to the old file descriptor (now pointing to access_log.1) because it never reopened the log file. Sending a USR1 or HUP signal to Apache causes it to close and reopen its log files, creating a new access_log and writing new entries there. This is the standard method for log rotation with Apache and other daemons that keep file handles open.

Answer

Modify the Apache configuration to set the 'RotateLogs' directive and restart the service.

Answer

Change the logrotate frequency to 'weekly' so that the log is not rotated as often.

Answer

Set the 'copytruncate' directive in the logrotate configuration to copy the log file and truncate the original, so Apache can continue writing without interruption.

Question 6

A system administrator notices that the system's syslog messages are not being written to /var/log/messages. The rsyslog service is running. The administrator wants to check the configuration syntax of rsyslog. Which command should be used?

Accepted Answer

rsyslogd -N. The correct command is `rsyslogd -N` because the `-N` option performs a configuration syntax check without starting or restarting the rsyslog daemon. This allows the administrator to validate the rsyslog configuration file for errors before applying changes, ensuring that syslog messages will be written correctly to /var/log/messages.

Answer

rsyslogd -d

Answer

rsyslogd -f

Answer

rsyslogd -v

Question 7

You are a system administrator for a small company running a web server on Ubuntu 20.04 LTS. The web server application was installed using apt from the official repositories. Recently, a critical security patch was released for the web server package. You run 'apt update' and 'apt upgrade' but the package is not upgraded. You check the package status with 'apt-cache policy <package>' and see that the installed version is 2.4.41-4ubuntu3.6, and the candidate version is the same. The latest patched version in the repository is 2.4.41-4ubuntu3.7. You verify that the system has internet connectivity and that the repository URLs in /etc/apt/sources.list are correct. What is the most likely reason the upgrade is not being offered?

Accepted Answer

Run 'apt-mark unhold ' and then 'apt upgrade'.. The most likely reason is that the package has been placed on hold using 'apt-mark hold', which prevents it from being upgraded even when a newer version is available in the repository. Running 'apt-mark unhold ' removes this hold, allowing 'apt upgrade' to proceed normally.

Answer

Add the universe repository to sources.list and run 'apt update'.

Answer

Use 'apt dist-upgrade' instead of 'apt upgrade'.

Answer

Run 'apt install <package>' which will force the upgrade.

Question 8

An administrator needs to extend a logical volume by 10GB. The volume group has available physical extents. Which command should be used?

Accepted Answer

lvextend -L +10G /dev/vg/lv. The `lvextend` command with the `-L +10G` flag increases the size of the existing logical volume `/dev/vg/lv` by exactly 10 GB, using available physical extents from the volume group. This is the standard LVM command for extending a logical volume without recreating it.

Answer

lvcreate -L 10G /dev/vg/lv

Answer

vgextend /dev/vg/lv -L +10G

Answer

lvresize -L 10G /dev/vg/lv

Question 9

A technician is troubleshooting a system that fails to boot with the error 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. What is the most likely cause?

Accepted Answer

The kernel lacks the necessary driver for the storage controller.. The error 'VFS: Unable to mount root fs on unknown-block(0,0)' indicates that the kernel cannot locate or access the root filesystem. This typically occurs because the kernel lacks the necessary driver (module) for the storage controller (e.g., SATA, SCSI, NVMe) that the root device is connected to, so it cannot read the partition table or mount the root filesystem.

Answer

The init binary is missing or corrupted.

Answer

The root filesystem is corrupted and needs fsck.

Answer

The boot loader is not installed correctly.

Question 10

An administrator notices that a large file on an ext4 filesystem is taking up more disk space than expected based on its size. Which command would show the actual disk usage (block allocation) of the file?

Accepted Answer

du -h. (du -h) is correct because du (disk usage) reports the actual disk space consumed by a file, including allocated blocks, which can be larger than the file's logical size due to block size overhead, fragmentation, or sparse file handling. On ext4, the default block size is 4096 bytes, so a 1-byte file occupies 4096 bytes on disk, and du reflects this allocation.

Answer

ls -l

Answer

df -h

Answer

stat

Question 11

Refer to the exhibit. A user runs 'python --version' and gets 'Python 3.9.1'. Which command would run Python 2 instead?

Accepted Answer

python2. On many Linux distributions, Python 2 and Python 3 are installed side by side, with the `python` command typically linked to Python 2 (or sometimes Python 3, depending on the distribution). However, in this scenario, `python --version` returns 'Python 3.9.1', indicating that `python` is linked to Python 3. To explicitly run Python 2, you must use the `python2` command, which is the standard binary name for Python 2.x installations.

Answer

python --version2

Answer

python3

Answer

python2 --version

Question 12

A company's server administrator needs to replace an existing DNS server (192.168.1.10) with a new one (192.168.1.20). Which file must be updated on all DHCP clients to ensure they use the new DNS server?

Accepted Answer

/etc/dhcp/dhcpd.conf. The DHCP server configuration file /etc/dhcp/dhcpd.conf contains the 'option domain-name-servers' directive that specifies which DNS servers are handed out to DHCP clients. When a client renews its lease, it receives the new DNS server IP (192.168.1.20) from the DHCP server, updating the client's /etc/resolv.conf automatically. This is the proper way to centrally manage DNS server assignments across all DHCP clients.

Answer

/etc/resolv.conf

Answer

/etc/nsswitch.conf

Answer

/etc/hosts

Question 13

Which TWO commands can be used to display the current firewall rules in a system using nftables? (Choose two.)

Accepted Answer

nft list ruleset. `nft list ruleset` is the primary command in nftables to display the entire ruleset, including all tables, chains, and rules, regardless of the address family. Option D is also correct because `nft list table inet filter` specifically displays the rules within the 'filter' table of the 'inet' family, which is a valid way to show a subset of the firewall rules. Both commands rely on the nftables framework, which is the modern replacement for iptables on Linux.

Answer

systemctl status nftables

Answer

iptables -L -n

Answer

firewall-cmd --list-all

Question 14

Refer to the exhibit. A user tries to write to /mnt/usb/myfile.txt as a non-root user and receives a permission denied error. What is the most likely reason?

Accepted Answer

The vfat filesystem does not support Unix permissions, and the mount options (fmask/dmask) restrict write access to root only. The vfat filesystem does not store Unix-style permissions; instead, it relies on mount options like fmask and dmask to set the effective permissions for all files and directories. If these masks are set to restrict write access to root only (e.g., fmask=0133), non-root users will receive a 'permission denied' error even if the filesystem is mounted read-write. This is a common cause of write failures on USB drives formatted with FAT/VFAT.

Answer

The filesystem is mounted read-only

Answer

The filesystem is mounted with the 'noexec' option, preventing write

Answer

The file's permissions are 644, so the user does not have write access

Question 15

A database server on a Linux system is configured to listen on TCP port 3306. The administrator wants to restrict access to the database server to only the local network (192.168.1.0/24) using iptables. Which of the following iptables rules achieves this?

Accepted Answer

iptables -A INPUT -p tcp --dport 3306 -s 192.168.1.0/24 -j ACCEPT. It adds an INPUT chain rule that accepts TCP traffic destined for port 3306 only when the source address is within the 192.168.1.0/24 subnet. This effectively restricts incoming database connections to the local network, while all other sources are implicitly dropped by the default INPUT policy or subsequent rules.

Answer

iptables -A INPUT -p tcp --dport 3306 -d 192.168.1.0/24 -j DROP

Answer

iptables -A OUTPUT -p tcp --dport 3306 -d 192.168.1.0/24 -j ACCEPT

Answer

iptables -A OUTPUT -p tcp --sport 3306 -s 192.168.1.0/24 -j ACCEPT

Question 16

An administrator needs to identify the device file for the first SATA SSD in a server. Which device file should they use?

Accepted Answer

/dev/sda. The first SATA SSD in a Linux system is typically assigned the device file /dev/sda. SATA drives use the SCSI subsystem via the libata driver, which names them /dev/sdX, with 'a' representing the first detected drive. This is the standard naming convention for SATA SSDs in modern Linux kernels.

Answer

/dev/hda

Answer

/dev/sdb

Answer

/dev/nvme0n1

Question 17

Refer to the exhibit. A system administrator runs 'ip route show default' and gets this output. What does it indicate?

Accepted Answer

The default route points to gateway 192.168.1.1 on interface eth0.. The command 'ip route show default' displays the default route entry in the kernel routing table. The output shows that the default route (destination 0.0.0.0/0) is via gateway 192.168.1.1 and uses interface eth0, meaning all traffic not matching a more specific route is sent to that gateway on that interface.

Answer

The DNS server is 192.168.1.1.

Answer

The system has no internet access.

Answer

The IP address of the system is 192.168.1.1.

Question 18

A DHCP server assigns IP addresses to clients, but some clients are not receiving the correct gateway. Which configuration file should be checked on the DHCP server?

Accepted Answer

/etc/dhcp/dhcpd.conf. The DHCP server configuration file on Linux systems is typically located at /etc/dhcp/dhcpd.conf (or /etc/dhcpd.conf on some older distributions). This file contains the subnet declarations, option definitions (such as option routers for the default gateway), and other parameters that the DHCP server uses to assign IP addresses and configuration details to clients. If clients are not receiving the correct gateway, the 'option routers' directive within this file should be checked and corrected.

Answer

/etc/dhcpd.conf

Answer

/etc/dhcp/dhclient.conf

Answer

/etc/resolv.conf

Question 19

You are the system administrator for a small business running a Red Hat Enterprise Linux 8 server that hosts a MySQL database and a web server. The server has two physical disks: a 240GB SSD (sda) with partitions sda1 (boot), sda2 (root), sda3 (swap), and a 1TB HDD (sdb) with a single partition sdb1 mounted at /var/lib/mysql. The server has been running for months without issues. However, this morning you receive alerts that the MySQL database is not accepting new connections. You log in and find that the /var filesystem is 100% full. You check the disk usage and see that /var/lib/mysql uses 90% of the space, but there are also large log files in /var/log/httpd. To free up space immediately and restore database service while planning a permanent solution, you decide to compress old log files and move some database archives to a backup server. After compressing several log files with gzip, the available space increases by only a few MB. You then delete some old database backups from /var/lib/mysql/backup, but the space usage shown by df remains unchanged. What is the most likely cause of this behavior?

Accepted Answer

Some processes have open file handles to the deleted files, preventing the space from being released.. When a file is deleted but still held open by a running process (e.g., the MySQL daemon or httpd), the filesystem does not release the disk space until all file handles are closed. In this scenario, the large log files in /var/log/httpd were compressed with gzip, but the original uncompressed files may still be open by the web server process, so deleting them (or the old database backups) does not free space until the process is restarted or the handles are released. This explains why df still shows 100% usage despite the deletions.

Answer

The disk quota for the mysql user is exceeded, so deletions do not reduce usage.

Answer

The SSD is not TRIM-enabled, so deleted blocks are not reclaimed.

Answer

The filesystem was remounted read-only due to errors, so deletions are not permanent.

Question 20

Which file is used by GRUB to load the kernel at boot time?

Accepted Answer

/boot/grub/grub.cfg. GRUB (GRand Unified Bootloader) reads its main configuration file, /boot/grub/grub.cfg, to determine which kernel to load and with what parameters. This file contains the menu entries, kernel paths, and initrd directives that GRUB uses at boot time. It is automatically generated by update-grub or grub-mkconfig based on scripts in /etc/grub.d/ and settings in /etc/default/grub.

Answer

/etc/grub.d/

Answer

/etc/default/grub

Answer

/boot/vmlinuz