EX200 Practice Test 26 — 15 Questions

Question 1

An administrator needs to enable swap on a newly created partition /dev/sdc1. Which two commands should be executed in order?

Accepted Answer

mkswap /dev/sdc1; swapon /dev/sdc1. Enabling swap on a new partition requires first formatting it as swap space with `mkswap`, then activating it with `swapon`. The `mkswap` command writes a swap signature to the partition, and `swapon` enables the kernel to use it as swap. Without `mkswap`, the partition lacks the proper swap filesystem structure and cannot be used for swapping.

Answer

mkswap /dev/sdc1; mount /dev/sdc1

Answer

swapon /dev/sdc1; mkswap /dev/sdc1

Answer

swapon /dev/sdc1; mount /dev/sdc1

Answer

mkfs.swap /dev/sdc1; swapon /dev/sdc1

Question 2

Order the steps to create a new LVM logical volume of 5 GiB named 'lv_data' in volume group 'vg_data'.

Accepted Answer

1. pvcreate, 2. vgcreate, 3. lvcreate, 4. mkfs, 5. mount. The correct sequence for creating an LVM logical volume is: first create physical volumes (PVs) with pvcreate, then the volume group (VG) with vgcreate, then the logical volume (LV) with lvcreate, then a filesystem on the LV with mkfs, and finally mount it. Any deviation from this order will fail because each step depends on the previous ones.

Answer

1. vgcreate, 2. pvcreate, 3. lvcreate, 4. mkfs, 5. mount

Answer

1. pvcreate, 2. lvcreate, 3. vgcreate, 4. mkfs, 5. mount

Answer

1. pvcreate, 2. vgcreate, 3. mkfs, 4. lvcreate, 5. mount

Question 3

An ext4 filesystem on a logical volume has been extended with lvextend, but df -h still shows the old size. Which command must be run to make the filesystem aware of the new size?

Accepted Answer

resize2fs. The `resize2fs` command is the correct tool to resize an ext4 filesystem after the underlying logical volume has been extended with `lvextend`. While `lvextend` expands the block device, the filesystem itself is not automatically aware of the new space; `resize2fs` adjusts the filesystem metadata to utilize the additional capacity.

Answer

lvextend -r

Answer

fsadm resize

Answer

xfs_growfs

Question 4

A system administrator needs to create a file system on /dev/sdb1 with a size of 10 GB and mount it persistently at /data. The file system should support extended attributes and be suitable for large files. Which command sequence achieves this?

Accepted Answer

mkfs.xfs /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data xfs defaults 0 0' >> /etc/fstab. Both XFS and ext4 support extended attributes by default in RHEL. However, XFS is optimized for large files and high performance, making it the recommended choice for this scenario. Option B correctly creates an XFS file system on /dev/sdb1, creates the mount point, mounts it immediately, and adds an fstab entry for persistence. Option C uses ext4, which is not as suitable for large files as XFS. Options A and D are incorrect due to wrong device or file system type.

Answer

mkfs.xfs /dev/sda1 && mkdir /data && echo '/dev/sda1 /data xfs defaults 0 0' >> /etc/fstab

Answer

mkfs.ext4 /dev/sdb1 && mkdir /data && mount /dev/sdb1 /data && echo '/dev/sdb1 /data ext4 defaults 0 0' >> /etc/fstab

Answer

mkswap /dev/sdb1 && mkdir /data && swapon /dev/sdb1 && echo '/dev/sdb1 /data swap defaults 0 0' >> /etc/fstab

Question 5

Which command sets the password maximum age for user 'bob' to 30 days?

Accepted Answer

chage -M 30 bob. Both `chage -M 30 bob` and `passwd -x 30 bob` are valid commands to set the maximum password age for user 'bob' to 30 days. `chage -M` is the commonly used and RHCSA-recommended tool for password aging, but `passwd -x` also works on Red Hat systems. Option C (`usermod -e`) sets account expiration, not password maximum age. Option D (`chage -W`) sets the warning period before expiry.

Answer

usermod -e 30 bob

Answer

chage -W 30 bob

Question 6

A technician is configuring a new Red Hat Enterprise Linux 9 server with multiple disks. They need to create a RAID 1 array using /dev/sda and /dev/sdb for the /boot partition. Which tool can create the RAID array and enable booting from it?

Accepted Answer

Use mdadm to create a RAID1 device and install GRUB on both disks. Mdadm is the standard Linux tool for creating software RAID arrays, including RAID 1 (mirroring). For the /boot partition, which must be readable by the bootloader, GRUB must be installed on both disks in the RAID 1 array to ensure bootability if one disk fails. mdadm creates the RAID device, and GRUB can then be installed on each disk's MBR or GPT partition.

Answer

Use parted to create a RAID array directly by specifying the RAID level

Answer

Use fdisk to create a RAID partition and then format with ext4

Answer

Use LVM to create a mirrored logical volume for /boot

Question 7

A developer is running Podman as a non-root user on a Red Hat Enterprise Linux 8 system. The developer successfully runs a container, but notices that after logging out of the SSH session, the container stops. The developer wants the container to continue running even after disconnecting from the SSH session. The container is a simple web server that listens on port 8080. The developer has already enabled lingering for the user account using 'loginctl enable-linger'. However, the container still stops upon logout. What additional step should the developer take to ensure the container persists after logout?

Accepted Answer

Create a systemd user service by running 'podman generate systemd --new --name mywebcontainer' and then enable and start the service with 'systemctl --user enable --now container-mywebcontainer.service'. Even with lingering enabled, a container started directly via `podman run` is tied to the user's login session and will be terminated when the session ends. To make the container persist independently of the SSH session, it must be managed as a systemd user service. The `podman generate systemd --new` command creates a systemd unit file that can be enabled with `systemctl --user`, ensuring the container starts automatically and continues running after logout.

Answer

Add the --restart=always flag to the podman run command

Answer

Use podman run --detach to run the container in the background

Answer

Use podman run -d to run the container in detached mode

Question 8

Which TWO commands can change the primary group of an existing user?

Accepted Answer

usermod -aG. None of the listed commands change the primary group of an existing user. The correct commands are `usermod -g` to change the primary group directly, or `groupmod -g` after ensuring the user is the only member of the group.

Answer

vigr

Answer

groupmems -a

Answer

useradd -G

Question 9

During boot, a server fails to mount an NFS filesystem listed in /etc/fstab. Which troubleshooting step should be taken first to isolate the issue?

Accepted Answer

Check the status of remote-fs.target with 'systemctl status remote-fs.target'. When an NFS filesystem fails to mount during boot, the first step is to check whether the remote-fs.target unit is active. This target is responsible for triggering the mounting of all remote filesystems (including NFS) after the network is available. If remote-fs.target is not active or has failed, the NFS mount will not be attempted, and troubleshooting should start here before investigating the NFS share itself.

Answer

Check the status of nfs-client.target with 'systemctl status nfs-client.target'

Answer

Try to manually mount the NFS share with 'mount /mnt/nfs'

Answer

View kernel messages with 'dmesg | grep -i nfs'

Question 10

A system has a logical volume that is thinly provisioned. The thin pool has a size of 100GB and the thin volume has a virtual size of 500GB. The administrator notices that the thin pool has only 5GB of data written so far. Which command will display the current data usage of the thin volume?

Accepted Answer

lvs -o lv_name,data_percent. The `lvs -o lv_name,data_percent` command specifically displays the percentage of the thin pool that has been consumed by the thinly provisioned logical volume. For thin volumes, the `data_percent` field reports the actual data usage relative to the thin pool's capacity, which is exactly what the administrator needs to see the current 5GB usage against the 100GB pool.

Answer

df -h /dev/mapper/vg01-thinvol

Answer

lsblk /dev/mapper/vg01-thinvol

Answer

lvdisplay /dev/vg01/thinvol

Question 11

Which command can be used to create a logical volume using all available free space in a volume group?

Accepted Answer

lvcreate -l 100%FREE -n lvdata vgdata. The `-l 100%FREE` flag allocates all unallocated physical extents in the volume group, which is the precise way to use all available free space. Option D (`-l 100%VG`) is incorrect because it attempts to allocate 100% of the volume group's extents, including those already used by other logical volumes, causing the command to fail if any extents are already allocated. Therefore, only option B is correct.

Answer

lvcreate --size 20G vgdata lvdata

Answer

lvcreate -L 20G -n lvdata vgdata

Answer

lvcreate -l 100%VG -n lvdata vgdata

Answer

lvcreate -L 100%FREE -n lvdata vgdata

Question 12

A script contains: lines=$(wc -l /etc/passwd); echo $((lines+1)). The output is unexpected. What is the problem?

Accepted Answer

lines contains a string including the filename, not just a number.. The command substitution `$(wc -l /etc/passwd)` outputs the line count followed by a space and the filename `/etc/passwd`. This entire string (e.g., `35 /etc/passwd`) is stored in the variable `lines`. When `$((lines+1))` attempts arithmetic expansion, it fails because the string is not a pure integer, causing the shell to treat it as 0 or produce an error, resulting in an unexpected output.

Answer

wc -l requires the -c option to count correctly.

Answer

The script has a syntax error in the echo command.

Answer

$((...)) cannot read a variable from command substitution.

Question 13

A user reports they cannot log in to a Linux system. Their account was recently created. The administrator checks /etc/passwd and sees the entry: jsmith:x:1001:1001::/home/jsmith:/sbin/nologin. What is the likely issue?

Accepted Answer

The user's shell is set to /sbin/nologin which prevents login. The user's shell is set to /sbin/nologin, which is a shell that displays a message and exits immediately, preventing interactive login. This is the direct cause of the login failure, as the system uses the shell field in /etc/passwd to determine the login program.

Answer

The user is locked due to expired password

Answer

The home directory does not exist

Answer

The user is not in any supplementary groups

Question 14

Which systemctl command configures a service to start automatically at boot without starting it now?

Accepted Answer

systemctl enable service. `systemctl enable service` creates the necessary symlinks in the systemd unit configuration directories (e.g., `/etc/systemd/system/multi-user.target.wants/`) to ensure the service starts automatically at boot, but it does not start the service immediately. This matches the requirement of configuring automatic startup without starting the service now.

Answer

systemctl set-default service

Answer

systemctl start service

Answer

systemctl reenable service

Question 15

A system administrator needs to ensure that a user named 'jdoe' can execute commands as root without being prompted for a password. Which configuration change should be made?

Accepted Answer

Add 'jdoe ALL=(ALL) NOPASSWD: ALL' to /etc/sudoers via visudo. The sudoers directive 'jdoe ALL=(ALL) NOPASSWD: ALL' grants user jdoe the ability to run any command as any user (including root) on any host without a password prompt. This configuration must be added using visudo to ensure syntax validation and prevent lockout. The NOPASSWD tag overrides the default password requirement for sudo.

Answer

Add jdoe to the wheel group and configure /etc/sudoers with '%wheel ALL=(ALL) ALL'

Answer

Set the UID of jdoe to 0

Answer

Add jdoe to the root group