Linux Virtualization Operations

Internal

• Linux Virtualization

Commands

virsh

virt-install	guestmount	guestunmount	virt-builder	virt-cat	virt-filesystems	virt-inspector
libguestfs	virt-copy-in	virt-copy-out	virt-customize	virt-df	virt-diff	virt-edit	virt-format
virt-log	virt-ls	virt-make-fs	virt-p2v	virt-rescue	virt-resize	virt-sparsify	virt-sysprep
virt-tar-out	virt-tar-in	virt-top	virt-v2v	virt-viewer	virt-what	virt-who	virt-xml-validate
qemu-img

Virtualization Host Storage Operations

Storage Pool Operations

• Disk-Based Storage Pool Configuration
• Partition-Based Storage Pool Configuration
• Directory-Based Storage Pool Configuration
• LVM-Based Storage Pool Configuration
• Storage Pool Deletion

Storage Volume Operations

• Storage Volume Creation
• Storage Volume Rename
• Storage Volume Cloning
• Storage Volume Deletion

Virtualization Host Network Operations

• Attaching a Guest Directly to a Virtualization Host Network Interface
• Modifying the Range of the DHCP Server for a Virtual Network
• Bridged Networking Configuration

Create a Guest Virtual Machine

Virtualization host storage and host-level networking must be configured as a prerequisite to creating guest virtual machines. Once storage pools and storage volumes are made available, and the networking is configured, guest virtual machines can be created with

virt-install

If the XML definition of a virtual machine is available, it can be created with:

virsh define

Start/Stop Guest VMs

   virsh start
   virsh shutdown

Connect to the Guest VM

   virsh console

Adding Storage to Guests

Adding Storage to Guests

Cloning a Guest VM

• Shut down the guest with virsh shutdown.
• Export the XML configuration with virsh dumpxml.
• Copy the XML definition under a new name, conventionally the name of the guest being built.
• Edit the XML as needed. Things you may want to change:
  • The name of the guest.
  • Remove the <uuid> line, a new UUID will be generated.
  • The amount of memory, specified as <memory>. Remove the <currentMemory> line.
  • The number of vCPUs allocated to the guest.
  • Remove the "cdrom" disk(s), if it is not going to be used.
  • Edit the <disk> definitions and adjust the names for the new storage volumes that will be provisioned for the new virtual machine. The virtual machine will definitely need a virtual machine image, stored in (usually) qcow2 format, end possible other block storage devices in raw format. Conventionally, the virtual machine image is stored in the main storage pool and it is named based on the name of the VM:

<disk type='file' device='disk'>
  <driver name='qemu' type='qcow2'/>
  <source file='/main-storage-pool/new-vm-name.qcow2'/>
  <target dev='vda' bus='virtio'/>
  ...
</disk>

<disk type='file' device='disk'>
  <driver name='qemu' type='raw'/>
  <source file='/main-storage-pool/'new-vm-name-docker.raw'/>
  <target dev='vdb' bus='virtio'/>
  ...
</disk>

• Clone the virtual machine image with the new name.
• Create any other storage volume that may be needed.
• Define the guest with virsh define.