EX200 Practice Test 2 — 10 Questions

Question 1

Which two are required to create a logical volume? (Choose two.)

Accepted Answer

Physical volume. A physical volume (PV) is required because it is the underlying storage device (e.g., a disk or partition) that LVM uses as a building block. Without a PV, there is no raw storage to allocate to a volume group. The volume group (VG) is then created from one or more PVs, and logical volumes (LVs) are carved from the VG. Both are mandatory steps in the LVM workflow.

Answer

Mount point

Answer

Filesystem

Answer

Partition

Question 2

Which TWO commands can be used to check the UUID of a filesystem on /dev/sda1?

Accepted Answer

lsblk -o UUID /dev/sda1. The `blkid` command directly queries the UUID of a block device from the libblkid cache or by reading the filesystem superblock, and `lsblk -o UUID` filters the lsblk output to show only the UUID column for the specified device. Both commands reliably retrieve the UUID of /dev/sda1.

Answer

e2label /dev/sda1

Answer

findmnt /dev/sda1

Answer

file -s /dev/sda1

Question 3

An administrator wants to add the user 'jane' to the supplementary groups 'wheel' and 'docker' without removing her from other groups. Which command should be used?

Accepted Answer

usermod -aG wheel,docker jane. Both `usermod -aG wheel,docker jane` and `usermod -a -G wheel,docker jane` are valid commands to append the user to the specified supplementary groups without removing her from other groups. The `-a` (append) flag can be combined with `-G` as `-aG` or provided separately (`-a -G`); both forms work identically. Option D (`usermod -G`) without `-a` would overwrite all supplementary groups, which is incorrect. Option A uses `groupmems`, which is not the standard command for this task and has incorrect syntax.

Answer

groupmems -a jane -g wheel,docker

Answer

usermod -G wheel,docker jane

Question 4

A company requires that SSH access from the external network (10.0.1.0/24) only be allowed to port 2222, and all other incoming traffic on the firewall should be dropped. Which firewalld rule should be applied to the external zone?

Accepted Answer

firewall-cmd --zone=external --add-rich-rule='rule family="ipv4" source address="10.0.1.0/24" port port="2222" protocol="tcp" accept' --permanent. It uses a rich rule to explicitly allow incoming TCP traffic on port 2222 from the 10.0.1.0/24 source network, which matches the requirement. The default target for the external zone is 'drop', so only explicitly permitted traffic is allowed; this rule ensures SSH on port 2222 is accepted while all other incoming traffic is dropped.

Answer

firewall-cmd --zone=external --add-service=ssh --permanent

Answer

firewall-cmd --zone=external --add-port=2222/tcp --permanent

Answer

firewall-cmd --zone=external --add-rich-rule='rule family="ipv4" source address="10.0.1.0/24" service name="ssh" accept' --permanent

Question 5

A user executes the script shown in the exhibit with './export_script.sh' and then runs 'echo $MY_VAR' in the same terminal. The output is empty. Why does this happen?

Accepted Answer

The script runs in a sub-shell, so exported variables are not available to the parent shell. When a script is executed with './export_script.sh', it runs in a sub-shell (a child process). The 'export' command within the script makes the variable available to that sub-shell and its own child processes, but not to the parent shell that invoked the script. Therefore, after the script exits, the variable MY_VAR is not defined in the parent shell's environment, resulting in an empty output from 'echo $MY_VAR'.

Answer

The script lacks execute permissions

Answer

The 'export' command is incorrectly placed after the variable assignment

Answer

The variable name should be in uppercase for it to be inherited

Question 6

Refer to the exhibit. The script produces the error shown. What is the most likely cause?

Accepted Answer

The variable $var is empty or unset.. The error 'unary operator expected' occurs in bash when the `[ ]` test command encounters an empty or unset variable on the left side of a comparison operator. Since `$var` is empty, the expression `[ $var = 'value' ]` expands to `[ = 'value' ]`, which is syntactically invalid because the `=` operator expects a left operand. Option D correctly identifies this as the root cause.

Answer

The = operator should be == for string comparison.

Answer

The string 'value' contains spaces.

Answer

The script is missing a valid shebang.

Question 7

Which two commands can be used to create a new partition on a disk without erasing existing partitions? (Choose two.)

Accepted Answer

fdisk. The `fdisk` command is a disk partitioning tool that allows you to create, delete, and modify partitions on a disk without erasing existing partitions, as long as there is unallocated space. It operates on the MBR or GPT partition table and writes changes only when explicitly saved, preserving existing partition entries.

Answer

mkswap

Answer

dd

Answer

wipefs

Question 8

An administrator wants to enable user disk quotas on an XFS filesystem mounted at /home. Which steps are required?

Accepted Answer

Add 'uquota' to /etc/fstab, remount, then run xfs_quota -x -c 'limit -u bsoft=500m bhard=1g user1' /home. XFS uses its own quota management tools, not the traditional `quotacheck`/`edquota` tools used by ext4. The correct procedure is to add the `uquota` mount option to `/etc/fstab`, remount the filesystem, and then use `xfs_quota` to set limits. The `xfs_quota` command with the `-x` (expert) flag and `-c` (command) flag allows setting user quotas directly, and the path `/home` specifies the filesystem.

Answer

Add 'usrquota' to /etc/fstab, remount, then run quotacheck and edquota

Answer

Quotas are not supported on XFS filesystems

Answer

Use mount -o uquota /home, then setquota -u user1 500M 1G /home

Question 9

Refer to the exhibit. An administrator runs 'mount -o remount,ro /data' and then 'mount' shows /data as read-only. Later, the system is rebooted. What is the state of /data after reboot?

Accepted Answer

/data will be mounted read-write because fstab specifies defaults (rw).. The `mount -o remount,ro /data` command changes the mount state only for the current session; it does not modify the `/etc/fstab` entry. The `defaults` mount option in fstab implies `rw` (read-write). After a reboot, the system reads fstab and mounts `/data` according to its persistent configuration, which is read-write.

Answer

/data will be mounted read-only because the remount persists across reboots.

Answer

/data will not be mounted because the filesystem is marked as read-only.

Answer

/data will be mounted read-only because the kernel remembers the last mount state.

Question 10

An administrator wants to allow user 'alice' to SSH into the server using key-based authentication only. Which configuration change is required?

Accepted Answer

Add alice's public key to ~alice/.ssh/authorized_keys and set PubkeyAuthentication yes in sshd_config.. SSH key-based authentication requires the user's public key to be placed in the user's `~/.ssh/authorized_keys` file, and the SSH daemon must have `PubkeyAuthentication yes` set in `/etc/ssh/sshd_config` to allow public key authentication. This configuration ensures that only users with the corresponding private key can authenticate as 'alice'.

Answer

Add alice's private key to /etc/ssh/authorized_keys.

Answer

Set PasswordAuthentication no in /etc/ssh/sshd_config and restart sshd.

Answer

Set PermitRootLogin prohibit-password.