Chapter 10. Working with Virtual Machines ("DO I KNOW THIS ALREADY?" QUIZ)

b. Explanation: KVM virtual machines run directly on top of the KVM hypervisor module and are not depended on the availability of the management program.

1. Which statement about KVM virtualization is not true? a. KVM is implemented through the Linux kernel. b. If you shut down the virt-manager utility, all virtual machines that are running within it will shut down as well. c. KVM virtualization is not installed by default. d. To configure a server as a KVM virtualization platform, you need a 64-bit operating system platform.

d. Explanation: The virsh destroy command is like pulling the power plug. It halts a virtual machine immediately with all the possible bad consequences of that.

10. You want to stop a virtual machine in the fastest way possible. Which command enables you to do this? a. virsh shutdown vmname b. virsh shutdown --now vmname c. virsh poweroff vmname d. virsh destroy vmname

b. Explanation: The libvirtd process provides the management interface to access KVM virtual machines.

2. Which process must be running to manage KVM virtual machines? a. kvmd b. libvirtd c. qemu d. virt-manager

a. Explanation: Hardware virtualization support needs to be present in your computer hardware. If it is not you cannot use KVM virtualization. On some computers, the feature is available, but not switched on by default. Switch it on through your computer BIOS setup.

3. How do you enable hardware virtualization support? a. Enable it in your server's BIOS b. Load the kvm module c. Start the libvirtd service d. Add virt=kvm at the kernel boot line in GRUB 2

c and d. Explanation: Look for the vmx flag in /proc/cpuinfo to verify the availability of hardware virtualization support or for the svm flag (for AMD cpus). The lscpu command shows the hypervisor mode a host is offering, and if used on a virtual machine it shows which type of virtualization platform this machine is used on.

4. How can you check whether hardware virtualization support is enabled on your server's CPU? a. cat /proc/kvm b. cat /proc/cpu c. cat /proc/cpuinfo d. lscpu

a. Explanation: The modprobe kvm command loads the KVM kernel module and all its dependencies. Do not use insmod kvm; that command will not load the kernel module dependencies as well.

5. What command enables you to load kernel KVM support? a. modprobe kvm b. insmod kmv c. lsmod kvm d. modload kvm

c. Explanation: The virtual machine disk files by default are stored in /var/lib/libvirt/images.

6. In which directory are virtual machine disk files stored by default? a. /etc/libvirt/images b. /var/lib/libvirt/fileystems c. /var/lib/libvirt/images d. /var/lib/qemu/images

d. Explanation: Virtual machine configuration files by default are stored in the directory/etc/libvirt/qemu.

7. What will be the (default) name of the configuration file that is used by the virtual machine vm1? a. /etc/kvm/vm1.xml b. /etc/libvirt/vm1.xml c. /etc/libvirt/kvm/vm1.xml d. /etc/libvirt/qemu/vm1.xml

c. Explanation: Automatic virtual machine startup can be enabled easily using the Virtual Machine Manager Boot options interface.

8. Which approach would you use to enable a virtual machine for automatic starting while booting? a. On the virtual machine properties, select the automatic boot option in Virtual Machine Manager. b. Use systemctl enable followed by the name of the virtual machine. c. From the Virtual Machine Manager Boot Options interface, under Autostart, select the Start Virtual Machine on Host Boot Up option. d. Add the virtual machine name as a boot option to GRUB on the hypervisor host.

c. Explanation: The virsh list command lists all virtual machines. Add --all to also show virtual machines that are not currently active.

9. From a command-line interface, which command enables you to list all virtual machines that are available, including VMs that haven't been started? a. virsh list b. virsh --list c. virsh list --all d. virsh list all