CompTIA Updated XK0-005 Exam Questions and Answers by shiloh

The ssh -X option enables X11 forwarding, which allows the user to run graphical applications on the remote server and display them on the local workstation. The user needs to specify the username, the server address, and the application name after the ssh -X command. The remote server also needs to have X11Forwarding enabled and xauth installed for this to work.

References:

• The web search result 8 explains how to run a GUI application through SSH by configuring both the SSH client and server.
• The web search result 6 provides a detailed answer on how to forward X over SSH to run graphics applications remotely, with examples and troubleshooting tips.
• The CompTIA Linux+ Certification Exam Objectives mention that the candidate should be able to “use SSH for remote access and management” as part of the System Operation and Maintenance domain1.

The command fsck.ext4 /dev/sda1 can be used to address the issue. The issue is caused by a corrupted filesystem on the /dev/sda1 partition. The error message shows that the filesystem type is ext4 and the superblock is invalid. The command fsck.ext4 is a tool for checking and repairing ext4 filesystems. The command will scan the partition for errors and attempt to fix them. This command can resolve the issue and allow the system to start. The other options are incorrect because they either do not fix the filesystem (partprobe or fdisk) or destroy the data on the partition (mkfs.ext4). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 10: Managing Storage, page 325.

The best way to prevent this issue from reoccurring in the future is to create a mount unit and enable it to be started at boot. A mount unit is a systemd unit that defines how and where a filesystem should be mounted. By creating a mount unit for the missing filesystem and enabling it with systemct1 enable, the administrator can ensure that the filesystem will be automatically mounted at boot time, regardless of whether it is listed in /etc/fstab or not. Syncing the mount units will not prevent the issue, as it will only synchronize the state of existing mount units with /etc/fstab, not create new ones. Mounting the filesystem manually will not prevent the issue, as it will only mount the filesystem temporarily, not permanently. Remounting all the missing filesystems will not prevent the issue, as it will only mount the filesystems until the next reboot, not after. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Disk Storage, page 457.

The administrator should modify the /etc/hosts file and change the db.example.com entry to 192.168.20.88 to address the issue. The /etc/hosts file is a file that maps hostnames to IP addresses on Linux systems. The file can be used to override the DNS resolution and provide a local lookup for hostnames. The dig output shows that the DNS returns the IP address 192.168.20.88 for the hostname db.example.com, which is the correct IP address of the system. The grep output shows that the /etc/hosts file contains an entry for db.example.com with the IP address 192.168.20.89, which is the wrong IP address of the system. This can cause a conflict and prevent the system from being accessed by the hostname. The administrator should modify the /etc/hosts file and change the db.example.com entry to 192.168.20.88, which is the correct IP address of the system. This will align the /etc/hosts file with the DNS and allow the system to be accessed by the hostname. The administrator should modify the /etc/hosts file and change the db.example.com entry to 192.168.20.88 to address the issue. This is the correct answer to the question. The other options are incorrect because they either do not modify the /etc/hosts file (modify the /etc/network file and change the db.example.com entry to 192.168.20.88 or modify the /etc/network file and change the db.example.com entry to 192.168.20.89) or do not change the IP address to the correct one (modify the /etc/hosts file and change the db.example.com entry to 192.168.20.89). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 12: Managing Network Connections, page 378.