You need to migrate a running QEMU VM to a remote host using live migration. Which command-line argument for QEMU-KVM initiates a migration to a target host at 192.168.1.50 on port 4444?
When migrating a Libvirt domain using 'virsh migrate --live', which option must be specified to ensure the guest's memory state is copied over the network?
You are troubleshooting a libvirt network issue where the virtual machines cannot reach the external gateway. The virtual network uses a NAT configuration. Which file would you inspect to verify the iptables rules generated by libvirt for this network?
You are performing a live migration of a VM using libvirt. The source and destination hosts share a common storage pool (NFS). Which option should be used with 'virsh migrate' to ensure only the memory state is transferred?
You are configuring a libvirt bridge network. Which file should you edit on a Debian/Ubuntu system to create a bridge interface 'br0' that includes 'eth0'?
You are configuring a virtual network with a bridge. You want to disable DNS services for that network. What XML element within the <network> definition do you remove or comment out?
When migrating a domain with virsh, which TWO of the following options can be used to ensure the migration is successful if the destination host has a different CPU architecture or feature set?
A KVM host runs a Windows guest that performs many random writes. The host's storage backend is a local LVM volume group. You want to avoid host-side fragmentation and reduce write amplification by preallocating the entire guest disk image at creation time. Which command creates a raw image named win10.img of 80 GiB with full allocation?
You are preparing a KVM guest for a live migration with virsh migrate --live and want the guest's disk writes to be tracked on the source host so that only dirty blocks are transferred after the memory copy begins. The guest disk is a raw image on a local LVM logical volume, and the destination host can reach the source's storage via a shared Fibre Channel LUN, but the LUN is not yet visible on the destination. Which action must you take on the source host before starting the migration to enable dirty-block tracking for this disk?
A KVM guest is configured with a virtio-blk disk backed by a qcow2 image on an NFS mount. During heavy write activity, the guest reports I/O errors and the host logs show 'nfs: server not responding'. You need to improve resilience so that transient NFS outages do not immediately cause guest I/O failures. Which QEMU block device cache mode should you set for the disk to allow the guest to continue operating during brief NFS stalls?
An administrator needs to create a new libvirt storage pool that stores disk images in a directory on the host and make it available to libvirt, but the directory does not yet exist. Which sequence of virsh commands correctly defines, starts, and activates the pool persistently?
A KVM host uses a storage pool of type 'logical' backed by an LVM volume group named vg_vms. You need to create a new 20 GB volume for a guest directly from this pool using virsh. Which command accomplishes this?
A running KVM guest named db1 has its root disk on a qcow2 image. You need to create a point-in-time snapshot of the guest's disk and memory state so it can be reverted later, while keeping the guest running. Which virsh command should you use?
You are configuring a Xen guest that requires direct hardware access to a specific network interface card. Which configuration parameter in the guest domain configuration file must be specified to enable PCI passthrough?
You are configuring a QEMU-KVM guest to use VirtIO-net. Which parameter in the QEMU command line correctly enables the virtio-net-pci device with a tap interface named tap0?
You are using libvirt to manage a QEMU VM. You want to pass a specific host USB device with vendor ID 1234 and product ID 5678 to the guest. Which XML element is used inside the <devices> block to define this?
A VM is hanging because of a specific hardware emulation bug in QEMU. You need to enable the 'qxl' video device to see if it resolves display issues. What is the XML tag to define the video device in the domain config?
You are using QEMU to emulate an ARM architecture on an x86_64 host. You need to ensure the guest has access to the host's filesystem directly without configuring network shares. Which option is the correct way to pass a directory through to the guest?
You are managing a Xen host and need to live-migrate a domain between two physical servers. The migration fails with a domain lock error. Which command is the standard way to initiate a live migration while ensuring the target host is prepared to receive the domain?
A libvirt storage pool of type 'dir' contains several qcow2 images. You want to create a new snapshot of an existing VM using virsh. Which command sequence is required to create an internal snapshot of the VM's current state?
You are configuring a virtual network in libvirt that allows VMs to communicate with each other and the host, but prevents them from accessing the external network. Which mode should you select for this network?
You are troubleshooting a libvirt migration that fails with 'Operation not supported: Migration requires a storage pool'. You need to perform a block migration where the storage is copied to the destination host. Which command-line flag enables this functionality?
You have a qcow2 disk image that is growing too large. You want to shrink the file size on the host while keeping the virtual disk the same size. Which steps must you perform first?
You are migrating a running KVM guest from hostA to hostB with virsh migrate --live. The migration fails immediately with 'error: internal error: Attempt to migrate guest to the same host'. Both hosts share the same NFS storage and have identical CPU models. Which condition most likely explains this failure?
You are configuring a KVM guest to use a paravirtualized clock and to report its IP addresses to the host so that libvirt can display them with virsh domifaddr. (Choose two.)
You are configuring a KVM host that will run several guests. You want each guest to be able to communicate with other guests and the host on the same subnet, while still allowing external hosts to reach the guests directly. You decide to use a libvirt virtual network with a bridge. Which libvirt network configuration element must be present to enable direct Layer 2 connectivity between the guests and the physical LAN?
A KVM host runs a Windows guest whose virtual disk is backed by a raw image file on an NFS mount. After a host reboot, the guest fails to start with 'Permission denied' on the disk path, although the file exists and is readable by root. The host uses SELinux enforcing mode. Which action resolves the problem?
You administer a KVM host running libvirt. A developer needs a guest to be able to communicate with the host directly over a private network without any NAT or bridging to the physical LAN. You decide to use libvirt's default virtual network. Which virsh command will display the XML definition of this default network so you can inspect its forwarding mode and DHCP range?
You are managing a KVM host and need to create a new storage pool that uses a directory on the host filesystem to store disk images. After creating the directory /var/lib/libvirt/images/extra, you want to define and start a libvirt storage pool named 'extra-pool' that uses this directory. Which sequence of virsh commands accomplishes this?
You need to create a new storage pool for KVM guests using the virsh command-line tool. The pool should use a directory on the host filesystem at /var/lib/libvirt/images/extra. Which command correctly defines and starts this pool?
You are troubleshooting a KVM guest that fails to boot after you changed its XML configuration. You want to verify and correct the guest's definition without starting it. Which TWO of the following actions are appropriate? (Choose two.)
You are troubleshooting a KVM guest that fails to start with the error 'unsupported configuration: CPU mode 'host-passthrough' requires KVM'. Which of the following is the most likely cause?
A KVM guest is configured with a virtio-blk disk and a virtio-net device. Under heavy network load the guest CPU shows high system time inside the guest, and the host shows high context-switch rates for the QEMU process. The administrator wants to reduce per-packet I/O overhead without changing the guest OS drivers. Which change is most appropriate?
You are setting up a KVM guest that requires very low latency for a real-time workload. You want to dedicate a physical CPU core to the guest and prevent the host from scheduling other tasks on that core. Which libvirt domain XML configuration achieves this?
A KVM host runs libvirt with a default storage pool at /var/lib/libvirt/images. You need to create a new qcow2-backed volume named 'app-disk.qcow2' with a virtual size of 40 GB inside the pool named 'default'. Which single virsh command accomplishes this?
You are preparing a KVM guest for a maintenance window and need to shut it down gracefully so the guest OS can flush buffers and stop services. Which virsh command should you use?
A guest was created with a 20 GB qcow2 disk and has been running for months. The administrator wants to give the guest additional space without recreating the disk, and the guest uses a single ext4 partition with no LVM. Which approach is valid with virsh and standard tools?
A production KVM guest uses a virtio-blk disk and experiences periodic I/O stalls during heavy write bursts. You want to switch the guest disk to virtio-scsi with multiple queues to improve parallelism without reinstalling the guest OS. Which change should you make to the domain XML?
You need to enable and configure a UEFI firmware boot for a new KVM guest on a libvirt host. Which TWO of the following steps are required? (Choose two.)
You are using QEMU/KVM with libvirt on a host and want to gracefully shut down a running domain named 'db01' so the guest OS performs its normal shutdown sequence. Which virsh command should you use?
An administrator is configuring a KVM host that will run a latency-sensitive guest. The goal is to reduce scheduling jitter and improve cache locality for that guest's vCPUs. Which TWO measures are appropriate? (Choose two.)
You are reviewing a KVM host and need to identify which of the following CPU features must be exposed to a guest to allow hardware-assisted nested virtualization inside that guest. (Choose two.)
A KVM host uses a bridged network 'br0' with the physical NIC enslaved. You want a guest to obtain an IP address from the same DHCP server as the host's physical LAN, without NAT. Which libvirt network interface definition in the domain XML achieves this?