EX200 Practice Test 4 — 25 Questions

Question 1

A developer runs the script shown in the exhibit and always sees 'Success' printed, even when the previous command fails. What is the most likely cause?

Accepted Answer

The $? variable captures the exit status of the [[ command, not the intended command. Option C is correct because the `[[ ]]` conditional construct is a shell keyword that itself produces an exit status. When `$?` is checked immediately after `[[ ]]`, it captures the exit status of the `[[ ]]` evaluation (which is 0 if the condition is true, 1 if false), not the exit status of the command that was run before the `[[ ]]`. Since the developer always sees 'Success' printed, the `[[ ]]` condition must be evaluating to true (exit status 0), causing `$?` to be 0 and the script to always take the success path, regardless of the actual previous command's result.

Answer

The [[ ]] syntax always evaluates to true

Answer

The $? variable is only set after external commands, not builtins

Answer

The $? variable always returns 0 in a conditional

Question 2

Based on the exhibit, what is the most likely cause of the failure?

Accepted Answer

Another process is already listening on port 22.. The failure message indicates that the SSH daemon cannot start because port 22 is already in use. Option B is correct because the error 'Address already in use' or 'bind to port 22 failed' directly points to another process occupying the port, preventing sshd from binding. This is a common port conflict scenario, not a configuration syntax or service enablement issue.

Answer

The SSH daemon is already running on another port.

Answer

The sshd configuration file has a syntax error.

Answer

The service is not enabled.

Question 3

A critical service must restart automatically after a crash. Which systemd directive should be added to the [Service] section of the service unit file?

Accepted Answer

Restart=always. Option C is correct because the `Restart=always` directive in the `[Service]` section of a systemd unit file instructs systemd to automatically restart the service whenever it exits, regardless of the exit status. This ensures the critical service recovers immediately after a crash without manual intervention, which is essential for high-availability requirements.

Answer

OnFailure=

Answer

Requires=

Answer

Wants=

Question 4

A user jdoe, who is a member of the group staff, reports they cannot access the directory /shared. The administrator runs getfacl /shared and receives the output shown. Which of the following explains the issue?

Accepted Answer

An ACL entry denies all permissions for jdoe. The getfacl output shows a user ACL entry for jdoe with permissions '---' (no read, write, or execute), which explicitly denies all access. This user-specific ACL entry overrides any group or other permissions, so jdoe cannot access /shared regardless of group staff membership.

Answer

The group staff does not have execute permission

Answer

The mask entry restricts group permissions

Answer

The directory is read-only for the owner

Question 5

Which TWO commands can be used to add a user to an existing supplementary group without removing them from other groups?

Accepted Answer

usermod -a -G group user. Option B is correct because the `usermod -a -G group user` command appends the user to the specified supplementary group without affecting their membership in other groups. The `-a` (append) flag must be used with `-G` to add the user to additional groups; without `-a`, the `-G` option replaces all supplementary group memberships with the listed groups.

Answer

groupmod -a user group

Answer

usermod -g group user

Answer

usermod -G group user

Question 6

Refer to the exhibit. An administrator tries to mount the partition /dev/sdc1 and gets a superblock error. What is the most likely cause?

Accepted Answer

The filesystem has not been created; mkfs.xfs was not run. The superblock error indicates that the kernel cannot read the filesystem metadata at the start of the partition. This most commonly occurs when no filesystem has been created on the partition — i.e., mkfs.xfs was never run on /dev/sdc1. Without a valid filesystem superblock, the mount command fails with a 'wrong fs type, bad option, bad superblock' message.

Answer

The filesystem is not recognized; need to install xfsprogs

Answer

The partition table is corrupted

Answer

The mount point /mnt/backup does not exist

Question 7

A Red Hat Enterprise Linux 9 system is configured as a router between an internal network (10.0.1.0/24) and a DMZ network (10.0.2.0/24). IP forwarding is enabled, and firewalld is active. The internal interface (eth0) is assigned to the 'internal' firewall zone, and the DMZ interface (eth1) is assigned to the 'dmz' zone. The requirement is that hosts on the internal network should be able to initiate connections to hosts in the DMZ, but the DMZ should not be able to initiate connections to the internal network. The administrator finds that traffic from internal to DMZ is being blocked. The internal zone has 'masquerade' enabled, and the dmz zone has no special settings. What is the most likely cause of the blocked traffic?

Accepted Answer

The internal zone is missing a rule to allow forwarded traffic to the DMZ. The internal zone is missing a rule to allow forwarded traffic to the DMZ. By default, firewalld zones have a default target of 'default' or 'reject', which drops forwarded traffic that does not match an explicit allow rule. Even though IP forwarding is enabled and the internal zone has masquerade, the firewall still filters forwarded packets based on zone rules. To permit traffic from internal to DMZ, a rule such as 'firewall-cmd --zone=internal --add-rich-rule="rule family=ipv4 forward-port port=any protocol=tcp to-port=any"' or more commonly a direct forward rule or policy object must be added to allow the forwarded traffic.

Answer

The dmz zone should be assigned to the internal interface

Answer

The internal zone has masquerade enabled, which is incorrect for a router

Answer

The dmz zone does not have masquerade enabled

Question 8

An administrator needs to compress a directory 'data' into an archive named backup.tar.gz using gzip compression. Which command should they use?

Accepted Answer

tar -czf backup.tar.gz data. Option D is correct because the `tar -czf` command creates a compressed archive: `-c` creates a new archive, `-z` filters the archive through gzip compression, `-f` specifies the archive filename `backup.tar.gz`, and `data` is the directory to archive. This produces a tarball compressed with gzip, matching the requirement exactly.

Answer

gzip -r data > backup.tar.gz

Answer

tar -cjf backup.tar.gz data

Answer

tar -xzf backup.tar.gz data

Question 9

A user reports that a script in their home directory fails to execute. The script has permissions -rw-r--r-- and is owned by the user. Which command will allow execution for the owner?

Accepted Answer

chmod u+x script.sh. The script currently has permissions `-rw-r--r--`, meaning the owner has read and write but not execute. To allow the owner to execute it, you need to add the execute permission for the owner only. `chmod u+x script.sh` adds the execute bit for the user (owner) without affecting group or others, which is the precise requirement.

Answer

chmod u+r script.sh

Answer

chmod a+x script.sh

Answer

chmod u-x script.sh

Question 10

A system administrator needs to configure a firewall using firewalld to allow incoming HTTPS traffic and deny incoming SSH traffic from a specific source IP 192.168.1.100. Which two commands should be run? (Choose two.)

Accepted Answer

firewall-cmd --add-service=https --permanent. Option C is correct because `firewall-cmd --add-service=https --permanent` adds the HTTPS service (TCP port 443) to the permanent firewall configuration, which is required to allow incoming HTTPS traffic persistently across reboots. The `--permanent` flag ensures the rule survives a reload or restart, and the `--add-service` option uses predefined service definitions from firewalld to simplify rule creation.

Answer

firewall-cmd --runtime-to-permanent

Answer

firewall-cmd --add-rich-rule='rule family=ipv4 source address=192.168.1.100 service name=ssh reject' --permanent

Answer

firewall-cmd --add-service=http --permanent

Question 11

Which TWO statements about Logical Volume Manager (LVM) metadata are correct?

Accepted Answer

The 'pvck' command can be used to check physical volume metadata.. Option A is correct because the 'pvck' command is specifically designed to check the metadata of physical volumes in LVM. It verifies the consistency and integrity of the PV metadata, including the volume group descriptor area (VGDA), without making changes. This is a diagnostic tool used before attempting repairs.

Answer

The 'pvs' command can repair corrupted metadata.

Answer

The 'fsck' tool is used to verify LVM metadata.

Answer

LVM metadata is stored in /etc/lvm directory.

Question 12

An administrator wants to add the two 2G disks (sdc and sdd) as physical volumes, extend the 'data' logical volume in volume group 'vg' by 2G, and grow the filesystem. Which sequence of commands should be used?

Accepted Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvextend -L +2G /dev/vg/lv_data; xfs_growfs /data. Option D is correct because it follows the correct sequence: create physical volumes on both disks, extend the volume group with both disks in a single command, extend the logical volume by exactly 2G using the `+` sign, and then grow the XFS filesystem using `xfs_growfs` with the mount point `/data`. The `+` in `lvextend -L +2G` is critical to add 2G rather than resize to 2G total, and `xfs_growfs` requires the mount point (or a block device) for XFS filesystems.

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvresize -L 2G /dev/vg/lv_data; xfs_growfs /data

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc /dev/sdd; lvextend -L +2G /dev/vg/lv_data; resize2fs /dev/vg/lv_data

Answer

pvcreate /dev/sdc /dev/sdd; vgextend vg /dev/sdc; vgextend vg /dev/sdd; lvextend -L +2G /dev/vg/lv_data; xfs_growfs /dev/vg/lv_data

Question 13

Which TWO commands can be used to add the user 'alice' to the supplementary group 'developers'?

Accepted Answer

gpasswd -a alice developers. Option A is correct because `gpasswd -a alice developers` adds the user 'alice' to the supplementary group 'developers' by appending her to the group's member list in /etc/group. Option C is correct because `usermod -aG developers alice` appends 'alice' to the supplementary group 'developers' without removing her from other supplementary groups, which is the intended behavior for adding a user to an additional group.

Answer

useradd -g developers alice

Answer

groupmod -a alice developers

Answer

usermod -g developers alice

Question 14

An administrator runs 'df -h' and sees the output above. The /data partition is nearly full. Which command will help identify the largest files in /data?

Accepted Answer

du -sh /data/*. Option D is correct because 'du -sh /data/*' calculates the total disk usage of each top-level item (files and directories) within /data, showing human-readable sizes. The asterisk expands to all immediate children, allowing the administrator to identify which specific files or directories consume the most space, which is exactly what is needed when /data is nearly full.

Answer

du -sch /data/*

Answer

du -sh /data

Answer

du -h --max-depth=1 /data

Question 15

A system administrator needs to run a container that remains running in the background and executes a web server. Which podman command will correctly run the container detached and map host port 8080 to container port 80?

Accepted Answer

podman run -d -p 8080:80 nginx. Option A is correct because `podman run -d` runs the container in detached mode (background), and `-p 8080:80` maps host port 8080 to container port 80, which is the standard port for the nginx web server. This allows external traffic on host port 8080 to be forwarded to the nginx service inside the container.

Answer

podman run -d -p 80:8080 nginx

Answer

podman run -d --expose 80 nginx

Answer

podman run -d -P 8080:80 nginx

Question 16

A containerized application requires persistent storage and must be able to run with SELinux enforcing. The administrator runs a container with the volume mount: `podman run -v /host/data:/container/data:Z myimage`. Which TWO statements are true about this configuration?

Accepted Answer

The volume mount persists after the container is removed.. Option C is correct because the `-v` flag with a bind mount persists the data in `/host/data` on the host filesystem even after the container is removed. The `:Z` flag tells Podman to relabel the host directory with a container-specific SELinux context, which is why Option E is also correct. This ensures the container can write to the mount point even when SELinux is enforcing.

Answer

The SELinux context of files in /host/data remains unchanged.

Answer

The /host/data directory is created automatically if it does not exist.

Answer

The container cannot write to /container/data if SELinux is enforcing.

Question 17

Match each SELinux mode to its behavior.

Accepted Answer

Enforcing: SELinux security policy is enforced.. SELinux has three modes: Enforcing (policy enforced, violations blocked), Permissive (policy not enforced, only warnings logged), and Disabled (SELinux turned off). Common confusions involve swapping behaviors between modes.

Answer

Enforcing: SELinux logs all actions but does not block them.

Answer

Permissive: SELinux enforces the policy and blocks violations.

Answer

Disabled: SELinux warns but does not block.

Question 18

Match each user/group management command to its function.

Accepted Answer

useradd: Creates a new user account. useradd creates users, usermod modifies them, userdel deletes them, and groupadd creates groups. Common confusions arise from similar command names.

Answer

useradd: Modifies an existing user account

Answer

usermod: Deletes a user account

Answer

userdel: Creates a new group

Answer

groupadd: Modifies an existing group

Question 19

An administrator needs to schedule a script to run every Monday, Wednesday, and Friday at 2:30 PM. Which cron expression should be used?

Accepted Answer

30 14 * * 1,3,5. Option A is correct because cron uses five fields (minute, hour, day-of-month, month, day-of-week). 2:30 PM is 14:30 in 24-hour format, so minute=30 and hour=14. The day-of-week field uses 0-7 (0 and 7 = Sunday), with Monday=1, Wednesday=3, Friday=5. The asterisks for day-of-month and month mean 'every day' and 'every month', so the expression `30 14 * * 1,3,5` runs the script at 2:30 PM on Monday, Wednesday, and Friday.

Answer

30 14 * * 1-5

Answer

14 30 * * 1,3,5

Answer

30 14 * * 0,2,4

Question 20

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

EX200 Practice Test 4 — 25 Questions

Exhibit

EX200 Practice Test 4 — 25 Questions

Exhibit