Chapter 29 Flashcards
Inspecting Cloud and Virtualization Services
Describe various VM tools.
The libvirt library is a popular software collection of virtualization management components. It includes an API, a daemon (libvirtd), and command-line utilities, such as virt-install and virsh. The virsh shell is one such tool provided by the libvirt library that allows you to manage a system’s virtual machines. The Virtual Machine Manager (also called VMM) is a lightweight desktop application for creating and managing virtual machines. You can initiate it from the command line by issuing the virt-manager command in a terminal emulator.
Explain bootstrapping utilities.
The kickstart installation method employs a kickstart file that contains all the bootstrap choices desired for a new system. Instead of starting from scratch, the anaconda file, /root/anaconda-ks.cfg, is available on Red Hat–based distros and can be modified to configure a kickstart file. Ubuntu distributions do not employ the kickstart installation method by default. Instead they use a bootstrapping product named preseed. openSUSE distros also have their own alternative, which is AutoYaST. The Canonical product, cloud-init, is a bootstrap utility that is available for local virtual machines as well as cloud-based ones.
Detail the various virtual storage options.
Virtual disks can be provisioned either thick or thin. Thick provisioning is a static setting where the virtual disk size is selected and the physical file(s) created on the physical disk is preallocated. Thin provisioning is grown dynamically, which causes the hypervisor to consume only the amount of disk space actually used for the virtual drive. Drives can be either persistent or temporary. Temporary volumes are discarded when the virtual machine is stopped, whereas persistent disks are kept not only when the VM is shut down but sometimes even after it is deleted. Blob storage refers to unstructured data offered on the Microsoft Azure cloud platform. This storage typically consists of images, streaming video and audio, big data, and so on. There are three blob types—block, append, and page.
Summarize virtual network configurations.
One network type is an overlay network. This network virtualization method uses encapsulation and communication channel bandwidth tunneling. Besides the typical network hardware, this network type employs virtual switches, tunneling protocols, and software-defined networking (SDN). Network adapters (NICs) also have many configuration virtualization options. A dual-homed virtual machine has two virtualized NICs. A host-only adapter connects to a virtual network contained within the virtual machine’s host system, and there is no connection to the external network. A bridged NIC makes the virtual machine like a node on the network to which the host system is attached. A NAT adapter creates a virtualized NAT router for the VM.
Which of the following is true concerning the libvirt library software collection? (Choose all that apply.)
Provides an API library for hypervisors Provides a complete hypervisor (VMM) application Provides the virsh and virsh-install utilities Provides the anaconda file used for bootstrapping Provides the libvirtd daemon for host systems
A, C, E. Options A, C, and E all contain true statements concerning the libvert library software collection and are therefore correct answers. This software collection does not provide a complete hypervisor application (though many hypervisors incorporate it), so option B is a wrong answer. Also the libvert library does not provide an anaconda file. Thus, option D is also an incorrect choice.
Carol wants to automate the management of her virtual machines via a Bash shell script. Which of the following utilities can she use in this script? (Choose all that apply.)
virsh virtinst virt-manage virt-install setvcpus
A, D. The virsh and virt-install utilities are ones that Carol can incorporate into her Bash shell script for managing her virtual machines. Therefore, options A and D are correct answers. virtinst is the name of a package file, which provides utilities such as virsh, and thus, option B is a wrong answer. Option C, virt-manage, is a made-up utility, making option C an incorrect answer. setvcpus is an argument you can use with the virsh utility, as opposed to a utility itself, so option E is an incorrect choice.
Nick is setting up a bootstrapping process on a RHEL system. He needs to store the installation tree. Which of the following are locations where he could store it? (Choose all that apply.)
Network location USB flash drive On AutoYaST Within the preseed directory With the kickstart file
A, B, E. The question does not indicate whether this system will be a virtual one or not. Typically for a physical installation, using the kickstart method, the installation tree is stored in a network location or removable media, such as a USB flash drive. Therefore, options A and B are correct answers. For a virtual machine installation, often the installation tree (or ISO) is stored alongside the kickstart file. Thus, option E is also a correct choice. AutoYaST and preseed are alternatives to kickstart for the openSUSE and Ubuntu distributions, so options C and D are incorrect choices.
Which of the following is true concerning the cloud-init product? (Choose all that apply.)
It was created and maintained by Microsoft. It is usable by cloud-based virtualization services. It is usable by cloud-based management operating systems. It is supported by most major Linux distributions. It is a bootstrap product.
B, C, D, E. Options B, C, D, and E are true statements about the cloud-init application and thus are correct answers. The only untrue is statement is in option A—the cloud-init product was created and is maintained by Canonical.
Ms. Danvers is designing a set of virtual machines for her company, Miracle. Currently, her host machine uses LVM but only has enough disk space for 1 TB of data. Her three VMs will need 200 GB of disk space immediately but are projected to grow to 300 GB each within the next year. What should she do?
Configure the three VMs to use persistent storage. Configure the three VMs to use temporary storage. Configure the three VMs to use thick provisioned storage. Configure the three VMs to use thin provisioned storage. Configure the three VMs to use blob storage.
D. Ms. Danvers’ best choice is to configure the three virtual machines to use thin provisioned storage. This method will allow the VMs to immediately consume 600 GB of the 1 TB of host disk space and grow over time as needed (which is called overprovisioning). As the VMs’ data grows, she can purchase additional disk space for her host machine and add it to the logical volume. Thus, option D is the correct answer. There is not enough information provided to determine whether or not the virtual machines’ disks should be configured as permanent or temporary, so options A and B are wrong answers. Thick provisioning would cause the three virtual machines to allocate 1.2 TB of disk space, which is not available, and thus, option C is an incorrect answer. Blob storage is used on Microsoft Azure virtual machines, and the question does not indicate that this is the cloud provider environment Ms. Danvers is using. Thus, option E is an incorrect choice.
Mr. Fury is a programming professor at Galactic University. This next semester he has chosen to use virtual machines for his students’ labs. The students will be creating a single program that they’ll work on throughout the entire semester. What is the best choice of disk storage for Mr. Fury’s student virtual machines?
Persistent storage Temporary storage Thick provisioned storage Thin provisioned storage Blob block storage
A. Because Mr. Fury’s programming students will be creating a single program that they are working on for the entire semester, the virtual machine storage needs to be configured as persistent. This will allow the students to access and modify their program on the virtual machine without having to re-create it each time their VM boots. Thus, option A is the correct choice. If Mr. Fury uses temporary storage, the students would have to re-create their program each time the VM boots, so option B is a wrong answer. Thickly or thinly provisioned storage needs are not discussed in this question, so options C and D are also incorrect answers. Blob storage is used on Microsoft Azure virtual machines, and the question does not indicate that this is the cloud provider environment Mr. Fury is using. Therefore, option E is an incorrect choice.
Which of the following is true about an overlay network? (Choose all that apply.)
It is a storage virtualization method. It is a network virtualization method. It is a method that employs encapsulation. It is a method that employs bandwidth tunneling. It is a method that employs page blobs.
B, C, D. Overlay networking is a network virtualization method that employs encapsulation as well as channel bandwidth tunneling. Therefore, options B, C, and D are correct answers. It is not a storage virtualization method, so option A is a wrong answer. Also, it does not employ page blobs (which are a Microsoft Azure platform storage option), so option E is also an incorrect choice.
Carol needs her virtual machines to all act as nodes on her host machine’s LAN and get their own IP address that they will use to send/receive network traffic. Which virtual NIC type should she configure on them?
Host-only Bridged NAT Multihomed Dual-homed
B. In order for Carol’s virtual machines to all act as nodes on her host machine’s LAN and get their own IP address that they will use to send/receive network traffic, she needs to configure them as bridged adapters. Thus, option B is the correct answer. A host-only configured NIC will not be able to communicate on the external network, so option A is a wrong answer. A NAT adapter will not allow the VMs to each operate as a node on the host machine’s network, so option C is a wrong choice. Multihomed and dual-homed are descriptions of the number of NICS employed by a VM, so options D and E are incorrect choices.
Ms. Danvers wants her three virtual machines’ IP address to be kept private, but she also wants them to communicate on the host machine’s network using its IP address. Which virtual NIC type should she configure on them?
Host-only Bridged NAT Multihomed Dual-homed
C. A virtual machine with a NAT configured adapter will have its IP address kept private and use the host machine’s IP address to communicate on the host machine’s network. Thus, option C is the correct answer. A host-only configured NIC will not be able to communicate on the external network, so option A is a wrong answer. A bridged adapter will not keep its assigned IP address private, so option B is also an incorrect answer. Multihomed and dual-homed are descriptions of the number of NICs employed by a VM, so options D and E are incorrect choices.
Nick has created five virtual machines on his host system. One virtual machine is employed as a firewall for the other four machines, which are confined with host-only adapters. The firewall VM operates on the host system’s network as a node. Which of the following describe his firewall adapter configuration? (Choose all that apply.)
Host-only Bridged NAT Multihomed Dual-homed
A, B, E. For Nick’s firewall VM to act as a firewall to the other four virtual machines, it would need a host-only adapter to communicate with the other machines on the local internal network. The firewall VM would also need a bridged NIC to act as a node on the host machine’s network. Because this firewall VM has two virtual NICs, it is considered to be dual-homed. Thus, options A, B, and E are correct choices. The NAT configuration type is not needed or employed in this scenario, so option C is a wrong answer. Also, since there are no more than two virtual adapters needed, it is not a multihomed (more than two) configuration, and option D is an incorrect choice.
