In an IaaS cloud, what is a common method for provisioning new computing instances with an operating system and software?
Correct Answer: C
Question 22
Virtualization of which hardware component is facilitated by CPUs supporting nested page table extensions, such as Intel Extended Page Table (EPT) or AMD Rapid Virtualization Indexing (RVI)?
Correct Answer: A
Explanation Nested page table extensions, such as Intel Extended Page Table (EPT) or AMD Rapid Virtualization Indexing (RVI), are hardware features that facilitate the virtualization of memory. They allow the CPU to perform the translation of guest virtual addresses to host physical addresses in a single step, without the need for software-managed shadow page tables. This reduces the overhead and complexity of memory management for virtual machines, and improves their performance and isolation. Nested page table extensions do not directly affect the virtualization of other hardware components, such as network interfaces, host bus adapters, hard disks, or IO cache. References: * Second Level Address Translation - Wikipedia * c - What is use of extended page table? - Stack Overflow * Hypervisor From Scratch - Part 4: Address Translation Using Extended ...
Question 23
FILL BLANK What LXC command starts a new process within a running LXC container? (Specify ONLY the command without any path or parameters.)
Correct Answer:
lxc-attach
Question 24
Which command within virsh lists the virtual machines that are running on the current host?
Correct Answer: C
Explanation The command virsh list is used to list all running domains (VMs) on the current host. The command virsh list --all can be used to list both active and inactive domains. The other options are not valid virsh commands. The command virsh list is a basic command that lists all running domains (VMs). You can also list all configured VMs by adding the --all option. This is useful if you want to see all VMs configured in the target hypervisor that you can use on subsequent commands1. References: * 1: 8 Linux virsh subcommands for managing VMs on the command line | Enable Sysadmin.
Question 25
Ifdocker stackis to be used to run a Docker Compose file on a Docker Swarm, how are the images referenced in the Docker Compose configuration made available on the Swarm nodes?
Correct Answer: C
Explanation Docker stack is a command that allows users to deploy and manage a stack of services on a Docker Swarm cluster. A stack is a group of interrelated services that share dependencies and can be orchestrated and scaled together. A stack is typically defined by a Compose file, which is a YAML file that describes the services, networks, volumes, and other resources of the stack. To use docker stack to run a Compose file on a Swarm, the user must first create and initialize a Swarm cluster, which is a group of machines (nodes) that are running the Docker Engine and are joined into a single entity. The Swarm cluster has one or more managers, which are responsible for maintaining the cluster state and orchestrating the services, and one or more workers, which are the nodes that run the services. When the user runs docker stack deploy with a Compose file, the command parses the file and creates the services as specified. However, docker stack does not build or upload the images referenced in the Compose file to any registry. Instead, it instructs the Swarm nodes to pull the images from a registry, which can be the public Docker Hub or a private registry. The user must ensure that the images are available in the registry before deploying the stack, otherwise the deployment will fail. The user can use docker build and docker push commands to create and upload the images to the registry, or use an automated build service such as Docker Hub or GitHub Actions. The user must also make sure that the image names and tags in the Compose file match the ones in the registry, and that the Swarm nodes have access to the registry if it is private. By pulling the images from a registry, docker stack ensures that the Swarm nodes have the same and latest version of the images, and that the images are distributed across the cluster in an efficient way. The other options are not correct. Docker stack does not build the images locally or on the Swarm nodes, nor does it copy or transfer the images to the Swarm nodes. Dockerstack also does not pass the images to the Swarm master, as this would create a bottleneck and a single point of failure. Docker stack relies on the registry as the source of truth for the images, and delegates the image pulling to the Swarm nodes. References: * Deploy a stack to a swarm | Docker Docs1 * docker stack deploy | Docker Docs2 * docker build | Docker Docs3 * docker push | Docker Docs4
