LPI 305-300 Dumps Questions Answers

The CPU architecture of a QEMU virtual machine is independent of the host system’s architecture. QEMU can emulate many CPU architectures, including x86, ARM, Alpha, and SPARC, regardless of the host system’s architecture1. This allows QEMU to run guest operating systems that are not compatible with the host system’s hardware. Therefore, option A is correct. QEMU virtual machines support multiple virtual CPUs in order to run SMP systems. QEMU uses the concept of virtual CPUs (vCPUs) to map the virtual machines to physical CPUs. Each vCPU is a thread that runs on a physical CPU core. QEMU allows the user to specify the number of vCPUs and the CPU model for each virtual machine. QEMU can run SMP systems with multiple vCPUs, as well as single-processor systems with one vCPU2. Therefore, option E is also correct. The other options are incorrect because they do not describe the CPU of a QEMU virtual machine. Option B is wrong because QEMU virtual machines can have more than one CPU with more than one core. Option C is wrong because QEMU does not require a dedicated physical CPU core for each virtual machine. QEMU can share the physical CPU cores among multiple virtual machines, depending on the load and the scheduling policy. Option D is wrong because QEMU does not use the term CPU, but vCPU, to refer to the virtual machines’ processors. References:

• QEMU vs VirtualBox: What’s the difference? - LinuxConfig.org
• QEMU / KVM CPU model configuration — QEMU documentation
• Introduction — QEMU documentation
• Qemu/KVM Virtual Machines - Proxmox Virtual Environment

 Vagrant is a tool that allows users to create and configure lightweight, reproducible, and portable development environments. Vagrant supports multiple providers, which are the backends that Vagrant uses to create and manage the virtual machines. By default, VirtualBox is the default provider for Vagrant. VirtualBox is still the most accessible platform to use Vagrant: it is free, cross-platform, and has been supported by Vagrant for years. With VirtualBox as the default provider, it provides the lowest friction for new users to get started with Vagrant. However, users can also use other providers, such as VMware, Hyper-V, Docker, or LXC, depending on their preferences and needs. To use another provider, users must install it as a Vagrant plugin and specify it when running Vagrant commands. Users can also change the default provider by setting the VAGRANT_DEFAULT_PROVIDER environmental variable. References:

• Default Provider - Providers | Vagrant | HashiCorp Developer1
• Providers | Vagrant | HashiCorp Developer2
• How To Set Default Vagrant Provider to Virtualbox3

The option dom0_mem is used to set the initial and maximum memory size of the Domain-0, which is the privileged domain that starts first and manages the unprivileged domains (DomU) in Xen. The option dom0_mem must be specified in the bootloader configuration, such as GRUB or GRUB2, when Xen is booted. This ensures that the Domain-0 kernel can allocate memory for storing memory metadata and network related parameters based on the boot time amount of memory. If the option dom0_mem is not specified in the bootloader configuration, the Domain-0 will use all the available memory on the host system by default, which may cause performance and security issues. References:

• Managing Xen Dom0′s CPU and Memory
• Xen Project Best Practices
• Dom0 Memory — Where It Has Not Gone