305-300 Exam Dumps : LPIC-3: Virtualization and Containerization - Exam 305, version 3.0

Cloud-init is a tool that processes configurations and runs through five stages during the initial boot of Linux VMs in a cloud. It allows users to customize a Linux VM as it boots for the first time, by applying user data to the instance. User data can include scripts, commands, packages, files, users, groups, SSH keys, and more. Cloud-init can also interact with various cloud platforms and services, such as Azure, AWS, OpenStack, and others. The purpose of cloud-init is to prepare the generic image of an laaS instance to fit a specific instance’s configuration, such as hostname, network, security, and application settings. References:

• Cloud-init - The standard for customising cloud instances
• Understanding cloud-init - Azure Virtual Machines
• Tutorial - Customize a Linux VM with cloud-init in Azure - Azure Virtual Machines

The unshare command is used to run a process in a new Linux namespace12. It takes one or more flags to specify which namespaces to create or unshare from the parent process1. For example, to run a shell in a new mount, network, and PID namespace, one can use:

unshare -mnp /bin/bash

References:

• 1: unshare(1) - Linux manual page - man7.org
• 2: A gentle introduction to namespaces in Linux - Packagecloud

 The correct command to move the libvirt domain web1 from the current host system to the host system host2 is virsh migrate web1 qemu+ssh://host2/system. This command uses the virsh migrate command, which initiates the live migration of a domain to another host1. The first argument is the name of the domain to migrate, which in this case is web1. The second argument is the destination URI, which specifies the connection to the remote host and the hypervisor to use2. In this case, the destination URI is qemu+ssh://host2/system, which means to use the QEMU driver and connect to host2 via SSH, and use the system instance of libvirtd3. The other options are incorrect because they either use invalid commands or arguments, such as node-update, pool-add, patch, or cp, or they do not specify the destination URI correctly. References: