EX200 Deploy, configure, and maintain systems Practice Test 4 — 15 Questions

Question 1

A technician needs to create a new group named 'developers' with GID 5000. Which command accomplishes this?

Accepted Answer

groupadd -g 5000 developers. The `groupadd -g 5000 developers` command explicitly sets the GID to 5000 for the new group named 'developers'. The `-g` option specifies the numeric group ID, which is required to meet the technician's exact requirement.

Answer

groupadd -r developers

Answer

useradd -g developers

Answer

groupadd developers

Question 2

An administrator extends a logical volume by 5GB. The filesystem is XFS. Which command must be run to make the additional space available?

Accepted Answer

xfs_growfs /mount. After extending a logical volume with lvresize, the XFS filesystem does not automatically recognize the new space. The xfs_growfs command must be run on the mounted filesystem to expand it to fill the enlarged logical volume. This command can target the mount point directly and works online without unmounting.

Answer

mount -o remount /mount

Answer

resize2fs /dev/vg/lv_root

Answer

lvresize -L +5G /dev/vg/lv_root

Question 3

A system fails to boot with an error about a missing ext4 filesystem. From the rescue environment, which command should be run to attempt automatic repair of all filesystems?

Accepted Answer

fsck -A -y. `fsck -A -y` automatically checks all filesystems listed in `/etc/fstab` (the `-A` flag) and answers 'yes' to any repair prompts (the `-y` flag), making it the most appropriate command for automatic repair of all filesystems from a rescue environment. The error indicates a missing ext4 filesystem, and this command will attempt to repair any ext4 (or other) filesystem issues without manual intervention.

Answer

fsck /dev/sda1

Answer

debugfs -R 'repair'

Answer

e2fsck -p

Question 4

Which THREE of the following are common steps to configure a system to automatically mount an NFS share at boot?

Accepted Answer

Ensure nfs-utils is installed. B is correct because the NFS client functionality in Red Hat Enterprise Linux is provided by the nfs-utils package. Without this package installed, the system lacks the necessary tools (such as mount.nfs and rpcbind) to mount NFS shares, making it impossible to configure automatic mounting at boot.

Answer

Run 'mount -a' after boot

Answer

Configure /etc/exports

Question 5

Which TWO files are essential in the /boot directory for the kernel to boot?

Accepted Answer

initramfs. The initramfs (initial RAM filesystem) is essential because it contains the necessary drivers and tools to mount the root filesystem before the kernel can take over. Without it, the kernel would not be able to access the storage device containing the root partition, especially when using filesystems or hardware that require kernel modules not built into the kernel itself.

Answer

fstab

Answer

grub.cfg

Answer

kernel

Question 6

Refer to the exhibit. An administrator needs to free up space in the /backup filesystem. Which of the following actions would be MOST effective?

Accepted Answer

Remove unnecessary files in /backup. The most direct way to free up space in the /backup filesystem is to remove unnecessary files stored there. This action immediately reclaims available space without altering the underlying logical volume or affecting other filesystems.

Answer

Increase the size of the logical volume

Answer

Delete old log files in /var/log

Answer

Use lvreduce to shrink the logical volume

Question 7

Refer to the exhibit. A web server must also accept HTTPS traffic on port 8443. Which command should the administrator run to permanently open this port?

Accepted Answer

firewall-cmd --add-port=8443/tcp --permanent && firewall-cmd --reload. It uses `--add-port=8443/tcp` to open a non-standard port (8443) for HTTPS traffic, applies the `--permanent` flag to persist the rule across reboots, and then runs `--reload` to activate the change immediately without restarting the firewall service. Without `--reload`, the permanent rule would not take effect until the next firewall reload or system restart.

Answer

firewall-cmd --add-service=8443/tcp --permanent

Answer

firewall-cmd --add-port=8443/tcp

Answer

firewall-cmd --add-port=8443/tcp --zone=public

Question 8

Refer to the exhibit. The SSH service has been running for 2 weeks. An administrator wants to restart the service without interrupting existing SSH connections. Which command should they use?

Accepted Answer

systemctl reload sshd. `systemctl reload sshd` sends a SIGHUP signal to the SSH daemon, instructing it to reload its configuration file without terminating existing connections. This is the standard method for applying configuration changes to services that support graceful reloads, such as sshd, which maintains persistent sessions by only re-reading its configuration and not restarting the process.

Answer

systemctl stop sshd; systemctl start sshd

Answer

kill -HUP 1234

Answer

systemctl restart sshd

Question 9

An administrator needs to ensure that the httpd service starts automatically after a system reboot and is set to start immediately without rebooting. Which command should be used?

Accepted Answer

systemctl enable --now httpd. `systemctl enable --now httpd` both creates the necessary symlinks to start the httpd service automatically at boot (enable) and starts the service immediately (--now) without requiring a reboot. This combines two operations into one command, satisfying both requirements in the question.

Answer

systemctl set-default httpd

Answer

systemctl add httpd

Answer

systemctl start --enable httpd

Question 10

A system administrator needs to restore the default SELinux security context on all files under /var/www/html after a misconfiguration. Which command should be used?

Accepted Answer

restorecon -R /var/www/html. The `restorecon -R /var/www/html` command restores the default SELinux security contexts on all files under /var/www/html by reading the file contexts defined in the SELinux policy (typically from /etc/selinux/targeted/contexts/files/file_contexts). The `-R` flag ensures recursive operation, making it the correct tool to fix misconfigured contexts without manually specifying a type.

Answer

setfiles -R /var/www/html

Answer

fixfiles -R /var/www/html

Answer

chcon -R -t httpd_sys_content_t /var/www/html

Question 11

An administrator has a logical volume 'lv_data' in a volume group 'vg_data' with a filesystem. The administrator needs to reduce the size of 'lv_data' by 2GB. Which sequence of commands should be performed?

Accepted Answer

umount, e2fsck -f, resize2fs, lvreduce. Reducing a logical volume with a filesystem requires a specific sequence: first unmount the filesystem to ensure no writes occur, then run e2fsck -f to force a filesystem check and ensure consistency, then use resize2fs to shrink the filesystem to the desired size, and finally lvreduce to shrink the logical volume itself. This order prevents data corruption by resizing the filesystem before the underlying block device.

Answer

lvreduce, resize2fs, e2fsck, umount

Answer

resize2fs, lvreduce, umount, e2fsck

Answer

umount, lvreduce, resize2fs, e2fsck

Question 12

A system administrator wants to allow incoming HTTPS traffic on the default zone of firewalld. Which command should be used?

Accepted Answer

firewall-cmd --add-service=https --permanent. The `--add-service=https` option adds the predefined HTTPS service (port 443/tcp) to the firewalld configuration. The `--permanent` flag ensures the rule persists across reboots. By default, the command applies to the default zone if no zone is specified, which matches the requirement to allow HTTPS traffic on the default zone.

Answer

firewall-cmd --add-port=443/tcp --zone=public --permanent

Answer

firewall-cmd --enable-service=https

Answer

firewall-cmd --add-rule=allow https

Question 13

An administrator wants to optimize system performance for a database workload. Which tool should be used to select a performance profile?

Accepted Answer

tuned-adm profile throughput-performance. C is correct because `tuned-adm profile throughput-performance` selects a Tuned performance profile optimized for high throughput, which is suitable for database workloads that benefit from increased I/O and network performance. Tuned is the systemd-based dynamic system tuning daemon in RHEL that adjusts kernel parameters, disk schedulers, and other settings based on the selected profile.

Answer

performance-tune --profile database

Answer

setroubleshoot

Answer

systemctl set-profile database

Question 14

An administrator needs to create a network bond interface 'bond0' with two slave interfaces 'eth0' and 'eth1' using active-backup mode. Which set of commands is correct?

Accepted Answer

nmcli con add type bond ifname bond0 mode active-backup; nmcli con add type bond-slave ifname eth0 master bond0; nmcli con add type bond-slave ifname eth1 master bond0. The commands create a bond interface with active-backup mode using nmcli. First, `nmcli con add type bond ifname bond0 mode active-backup` creates the bond with the required mode. Then, `nmcli con add type bond-slave ifname eth0 master bond0` and similarly for eth1 add the slave interfaces. This is the correct set of commands that fulfills the requirement. Option A uses an alternative syntax but does not set the mode. Option B involves manual editing, and option C uses teamd, which is for teaming, not bonding.

Answer

nmcli con add type bond ifname bond0; nmcli con add type ethernet ifname eth0 master bond0 slave-type bond

Answer

Edit /etc/sysconfig/network-scripts/ifcfg-bond0 and ifcfg-eth0 manually

Answer

teamd -d -c '{"device":"bond0","runner":{"name":"activebackup"},"ports":{"eth0":{},"eth1":{}}}'

Question 15

An administrator wants to view only the error messages from the kernel ring buffer since last boot. Which command should be used?

Accepted Answer

journalctl -k -p err. `journalctl -k -p err` filters the kernel messages (`-k`) from the systemd journal by priority level `err` (error), showing only error-level kernel messages since the last boot. This is the standard way to view kernel error messages in modern RHEL/CentOS systems using systemd-journald.

Answer

cat /var/log/kernel-errors

Answer

dmesg -p err

Answer

systemctl status kernel