EX200 Practice Test 6 — 10 Questions

Question 1

A web server is running in enforcing mode with SELinux, but Apache cannot read content in a custom directory /web. The directory has been labeled correctly with httpd_sys_content_t. However, access is still denied. What is the most likely cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The directory has incorrect permissions of 700.. Even though the SELinux context is correctly set to httpd_sys_content_t, the directory has permissions of 700 (rwx------). This means only the owner (typically root) can read, write, or execute the directory. The Apache httpd process runs as the 'apache' or 'httpd' user, which is not the owner, so it is denied read access. SELinux enforces its own policy, but DAC (Discretionary Access Control) permissions are checked first; if DAC denies access, SELinux never gets to evaluate the context match.

Answer

SELinux boolean httpd_enable_homedirs is off.

Answer

The httpd process is running in permissive mode.

Answer

The files are labeled with default_t.

Question 2

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 3

A user complains that the 'ls' command no longer outputs colors. The administrator suspects a change in environment variables. Which command would help diagnose the issue?

Accepted Answer

env. The `env` command displays all current environment variables, which directly affect the behavior of commands like `ls`. The `ls` command uses the `LS_COLORS` environment variable to determine color output; if this variable is missing or altered, colors will not appear. Running `env` allows the administrator to inspect the current environment and identify if `LS_COLORS` has been changed or unset.

Answer

set

Answer

declare

Answer

alias

Question 4

A system administrator needs to allow members of the 'developers' group to run any command as root without being prompted for a password. Which sudoers configuration line should be added?

Accepted Answer

%developers ALL=(ALL) NOPASSWD: ALL. The line `%developers ALL=(ALL) NOPASSWD: ALL` grants all members of the 'developers' group (indicated by the `%` prefix) permission to run any command as any user (including root) via sudo without being prompted for a password. The `NOPASSWD` tag is the key directive that bypasses password authentication, which directly matches the requirement to run commands as root without a password.

Answer

%developers ALL=(root) PASSWD: ALL

Answer

developers ALL=(ALL) NOPASSWD: ALL

Answer

%developers ALL=(ALL) ALL

Question 5

What is the default filesystem type in Red Hat Enterprise Linux 8?

Accepted Answer

XFS. In Red Hat Enterprise Linux 8, the default filesystem type is XFS. XFS is a high-performance 64-bit journaling filesystem that supports large files and filesystems, and it has been the default since RHEL 7. The Anaconda installer selects XFS by default for the root filesystem during a standard installation.

Answer

btrfs

Answer

ZFS

Answer

ext4

Question 6

Which command displays the current system time, timezone, and whether NTP synchronization is active?

Accepted Answer

timedatectl. The `timedatectl` command (option C) is the correct tool in Red Hat Enterprise Linux (RHEL) for querying and configuring system time, timezone, and NTP synchronization status. It displays the current local time, timezone, and whether NTP is active or enabled in a single, clear output, making it the standard utility for these tasks in systemd-based systems.

Answer

ntpq -p

Answer

date

Answer

cal

Question 7

An administrator has an XFS filesystem on a logical volume /dev/vg_data/lv_data mounted at /data. To extend the filesystem by 10GB, which sequence of commands is correct?

Accepted Answer

lvextend -L +10G /dev/vg_data/lv_data; xfs_growfs /data. For XFS filesystems, the logical volume must be extended first with `lvextend`, then the filesystem must be grown online using `xfs_growfs` with the mount point as the argument. XFS does not support shrinking and requires this specific order; `resize2fs` is only for ext2/3/4 filesystems.

Answer

lvextend -L +10G /dev/vg_data/lv_data; resize2fs /dev/vg_data/lv_data

Answer

xfs_growfs /data; lvextend -L +10G /dev/vg_data/lv_data

Answer

resize2fs /dev/vg_data/lv_data; lvextend -L +10G /dev/vg_data/lv_data

Question 8

Which THREE of the following are valid and recommended practices when writing shell scripts for RHEL?

Accepted Answer

Using 'local' keyword for variable declarations inside functions.. The 'local' keyword restricts a variable's scope to the function where it is declared, preventing unintended side effects on global variables. This is a recommended practice in RHEL shell scripting to maintain modularity and avoid namespace pollution.

Answer

Using 'set -e' to exit on non-zero exit codes.

Answer

Using the 'source' command instead of '.' for readability.

Question 9

During boot, a custom application fails because the /data file system is not mounted. Upon investigation, the administrator sees an error 'UUID=abc123 not found' in the logs. Which command should the administrator use to correct the /etc/fstab entry?

Accepted Answer

blkid /dev/sdb1. The error 'UUID=abc123 not found' indicates that the /etc/fstab entry for /data references a UUID that does not match any block device. The administrator needs to find the correct UUID of the actual partition (e.g., /dev/sdb1) and update the fstab entry. The `blkid /dev/sdb1` command displays the UUID (and filesystem type) of that specific device, allowing the administrator to copy the correct UUID into /etc/fstab.

Answer

mount -a

Answer

xfs_info /dev/sdb1

Answer

fdisk -l /dev/sdb1

Answer

lsblk -f /dev/sdb1

Question 10

A Red Hat Enterprise Linux system has a second disk /dev/sdb with a single partition /dev/sdb1 that was formatted as XFS and mounted at /mnt/backup. The administrator wants to change the filesystem on /dev/sdb1 to ext4 without losing existing data. Which steps should be taken in order?

Accepted Answer

Backup data, unmount, mkfs.ext4, remount, restore data. You cannot convert an XFS filesystem to ext4 in place; the only safe method is to back up the data, unmount the partition, create a new ext4 filesystem with mkfs.ext4, remount, and then restore the data. XFS and ext4 have fundamentally different on-disk structures (e.g., allocation groups vs. block groups, different journaling formats), so no in-place conversion tool exists.

Answer

Unmount, mkfs.ext4 /dev/sdb1, then mount

Answer

Use xfs_admin to change type

Answer

Use fsck.ext4 to convert in place