What XK0-006 Questions and Answers feature?

This issue falls under the Troubleshooting domain of the CompTIA Linux+ V8 objectives, specifically service startup failures and certificate-related errors. The provided output clearly indicates that the NGINX service fails during startup due to an inability to locate the private key file.

The critical error message is:

cannot load certificate key "/etc/pki/nginx/private/server.key": No such file or directory

This message confirms that NGINX is explicitly configured to look for the private key in the directory /etc/pki/nginx/private/. However, the directory listing shows that the private directory exists but is empty, while the server.key file is located in /etc/pki/nginx/ instead. Because NGINX cannot find the private key at the configured path, the configuration test (nginx -t) fails, and systemd prevents the service from starting.

Option C correctly identifies the root cause: the private key is not in the correct location. Moving server.key into /etc/pki/nginx/private/ (or updating the NGINX configuration to match the current location) would resolve the issue. Linux+ V8 documentation stresses that service failures often result from misaligned configuration paths rather than corrupted files.

The other options are incorrect. Option A incorrectly refers to renaming a certificate file and does not address the path issue. Option B suggests a key mismatch, which would generate a different SSL error rather than a “file not found” error. Option D is also incorrect because private keys should not have executable permissions like 0755; typically, they are restricted (for example, 0600) for security reasons.

Therefore, the web service is not responding because the private key file is not located in the directory expected by the NGINX configuration. The correct answer is C.

Creating backups is a core responsibility in Linux system management, and the Linux+ V8 objectives emphasize proper use of archiving and compression tools. The tar utility is the standard Linux tool for creating archive files, and it also supports compression through various options.

The command tar -cJf /backups/home.tar.xz /home/ correctly combines both archiving and compression in a single step. The -c option creates a new archive, -J specifies XZ compression, and -f allows the administrator to define the output file name. This results in a compressed archive of the entire /home/ directory, which is efficient for storage and transfer.

The other options are incorrect. cpio is an archiving tool but does not perform compression by itself without additional commands or pipelines. rsync -z compresses data during transfer but does not create an archive file. The dd command performs low-level copying of raw data and is not suitable for directory-based backups.

Linux+ V8 documentation highlights tar as the preferred utility for filesystem backups due to its flexibility, reliability, and support for multiple compression algorithms. Therefore, the correct answer is C.

Comprehensive and Detailed Explanation From Exact Extract:

To add a new physical disk to LVM, the disk must first be initialized as a physical volume using the pvcreate command. This prepares the new disk for use by the LVM subsystem. After initializing with pvcreate, you would use vgextend to add the new physical volume to an existing volume group.

Other options:

A. vgextend adds a physical volume to a volume group, but you must use pvcreate first.

B. lvextend is used to increase the size of a logical volume, not to add a new disk.

D. pvresize is used to resize an existing physical volume, not to create one.