XK0-005 Exam Dumps - CompTIA Linux+ Exam

The docker run -d --name web-01 httpd command will launch a container named web-01 in background mode. This command will create and start a new container from the httpd image, assign it the name web-01, and run it in detached mode (-d), which means the container will run in the background without attaching to the current terminal. The docker builder -f --name web-01 httpd command is invalid, as builder is not a valid docker command, and -f and --name are not valid options for docker build. The docker load --name web-01 httpd command is invalid, as load does not accept a --name option, and httpd is not a valid file name for load. The docker ps -a --name web-01 httpd command is invalid, as ps does not accept a --name option, and httpd is not a valid filter for ps. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 16: Virtualization and Cloud Technologies, page 499.

TRIM is a feature that allows the operating system to inform the SSD which blocks of data are no longer in use and can be wiped internally. This helps to maintain the SSD’s performance and endurance by preventing unnecessary write operations and reducing write amplification12. Running the corresponding command to trim the SSD drives, such as fstrim or blkdiscard on Linux, can help to solve the issue of slow writes by freeing up space and optimizing the SSD’s internal garbage collection34.

References: 1: What is SSD TRIM, why is it useful, and how to check whether it is turned on 2: How to Trim SSD in Windows 10 3: How to run fsck on an external drive with OS X? 4: How to Use the fsck Command on Linux

This is because the application server can ping the database server’s IP address, but not its hostname, which suggests that the DNS resolution is not working properly. DNS servers are responsible for translating hostnames into IP addresses, and vice versa. If the application server has incorrect or unreachable DNS servers configured, it will not be able to resolve the hostname of the database server and communicate with it.

To troubleshoot this issue, the systems engineer should check the DNS configuration on the application server, which is usually stored in the /etc/resolv.conf file. This file should contain valid nameserver entries that point to the DNS servers that can resolve the database server’s hostname. For example, a typical /etc/resolv.conf file may look like this:

nameserver 8.8.8.8 nameserver 8.8.4.4

These are the IP addresses of Google’s public DNS servers, which can be used as a fallback option if the default DNS servers are not working.

Alternatively, the systems engineer can use the nslookup or dig commands to test the DNS resolution of the database server’s hostname from the application server. These commands will query a specified DNS server and return the IP address of the hostname, or an error message if the resolution fails. For example, to query Google’s public DNS server for the IP address of comptia.org, the command would be:

nslookup comptia.org 8.8.8.8

or

dig comptia.org @8.8.8.8

Step-by-Step Comprehensive Detailed Explanation:

Command Explanation:

A: This command explicitly allows traffic from the 10.10.0.0/24 network to port 22 (SSH/SFTP).

Why Other Options are Incorrect:

B: Does not specify the source network.

C: Does not specify the port.

D: Syntax is invalid for ufw.

References:

CompTIA Linux+ Study Guide: Firewall Management

man ufw

The Requires=docker-repository.mount directive in the Docker service file ensures that the Docker service depends on the docker-repository.mount unit. If the mount is not available, Docker will not start. This guarantees that the necessary volume is mounted before the Docker service attempts to use it.

Comprehensive and Detailed Step-by-Step Explanation:

git push origin master pushes committed changes to the remote repository.

git stash temporarily saves changes but does not push them.

git commit -a commits changes but does not send them to the remote repository.

git add . stages changes but does not commit or push them.

The ping -c 1 192.168.47.44 command sends one ICMP echo request to the specified host to check its availability. If the host is down, there will be no response. This is the quickest way to confirm if a host is reachable. nmap -Pn can also be used to check a host status, but ping is faster and lighter.

The renice command changes the scheduling priority of a running process. By using renice -n 15, the administrator lowers the priority of the backup process, making it less CPU-intensive and reducing its impact on other system services. A positive niceness value (e.g., 15) lowers the priority, allowing other processes to receive more CPU time.