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Virtualization Guide / Managing virtual machines with libvirt / Guest installation
Applies to SUSE Linux Enterprise Server 15 SP6

10 Guest installation

  

A VM Guest consists of an image containing an operating system and data files and a configuration file describing the VM Guest's virtual hardware resources. VM Guests are hosted on and controlled by the VM Host Server. This section provides generalized instructions for installing a VM Guest. For a list of supported VM Guests refer to Chapter 7, Virtualization limits and support.

Virtual machines have few if any requirements above those required to run the operating system. If the operating system has not been optimized for the virtual machine host environment, it can only run on hardware-assisted virtualization computer hardware, in full virtualization mode, and requires specific device drivers to be loaded. The hardware that is presented to the VM Guest depends on the configuration of the host.

You should be aware of any licensing issues related to running a single licensed copy of an operating system on multiple virtual machines. Consult the operating system license agreement for more information.

10.1 GUI-based guest installation

  
Tip
Tip: Changing default options for new virtual machines

You can change default values that are applied when creating new virtual machines. For example, to set UEFI as the default firmware type for new virtual machines, select Edit › Preferences from Virtual Machine Manager's main menu, click New VM and set UEFI as the firmware default.

Specifying default options for new VMs
Figure 10.1: Specifying default options for new VMs
  

The New VM wizard helps you through the steps required to create a virtual machine and install its operating system. To start it, open the Virtual Machine Manager and select File › New Virtual Machine. Alternatively, start YaST and select Virtualization › Create Virtual Machines.

  1. Start the New VM wizard either from YaST or Virtual Machine Manager.

  2. Choose an installation source—either a locally available media or a network installation source. To set up your VM Guest from an existing image, choose import existing disk image.

    On a VM Host Server running the Xen hypervisor, you can choose whether to install a paravirtualized or a fully virtualized guest. The respective option is available under Architecture Options. Depending on this choice, not all installation options may be available.

  3. Depending on your choice in the previous step, you need to provide the following data:

    Local install media (ISO image or CDROM)

    Specify the path on the VM Host Server to an ISO image containing the installation data. If it is available as a volume in a libvirt storage pool, you can also select it using Browse. For more information, see Chapter 13, Advanced storage topics.

    Alternatively, choose a physical CD-ROM or DVD inserted in the optical drive of the VM Host Server.

    Network install (HTTP, HTTPS or FTP)

    Provide the URL pointing to the installation source. Valid URL prefixes are, for example, ftp://, http:// and https://.

    Under URL Options, provide a path to an auto-installation file (AutoYaST or Kickstart, for example) and kernel parameters. Having provided a URL, the operating system should be automatically detected correctly. If this is not the case, deselect Automatically Detect Operating System Based on Install-Media and manually select the OS Type and Version.

    Import existing disk image

    To set up the VM Guest from an existing image, you need to specify the path on the VM Host Server to the image. If it is available as a volume in a libvirt storage pool, you can also select it using Browse. For more information, see Chapter 13, Advanced storage topics.

    Manual install

    This installation method is suitable to create a virtual machine, manually configure its components and install its OS later. To adjust the VM to a specific product version, start typing its name, for example, sles—and select the desired version when a match appears.

  4. Choose the memory size and number of CPUs for the new virtual machine.

  5. This step is omitted when Import an Existing Image is chosen in the first step.

    Set up a virtual hard disk for the VM Guest. Either create a new disk image or choose an existing one from a storage pool (for more information, see Chapter 13, Advanced storage topics). If you choose to create a disk, a qcow2 image is created and stored under /var/lib/libvirt/images by default.

    Setting up a disk is optional. If you are running a live system directly from CD or DVD, for example, you can omit this step by deactivating Enable Storage for this Virtual Machine.

  6. On the last screen of the wizard, specify the name for the virtual machine. To be offered the possibility to review and make changes to the virtualized hardware selection, activate Customize configuration before install. Specify the network device under Network Selection. When using Bridge device, the first bridge found on the host is pre-filled. To use a different bridge, manually update the text box with its name.

    Click Finish.

  7. (Optional) If you kept the defaults in the previous step, the installation starts. If you selected Customize configuration before install, a VM Guest configuration dialog opens. For more information about configuring VM Guests, see Chapter 14, Configuring virtual machines with Virtual Machine Manager.

    When you are done configuring, click Begin Installation.

Tip
Tip: Passing key combinations to virtual machines

The installation starts in a Virtual Machine Manager console window. Certain key combinations, such as Ctrl–Alt–F1, are recognized by the VM Host Server but are not passed to the virtual machine. To bypass the VM Host Server, Virtual Machine Manager provides the “sticky key” functionality. Pressing Ctrl, Alt, or Shift three times makes the key sticky, then you can press the remaining keys to pass the combination to the virtual machine.

For example, to pass Ctrl–Alt–F2 to a Linux virtual machine, press Ctrl three times, then press Alt–F2. You can also press Alt three times, then press Ctrl–F2.

The sticky key functionality is available in the Virtual Machine Manager during and after installing a VM Guest.

10.1.1 Configuring the virtual machine for PXE boot

  

PXE boot enables your virtual machine to boot from the installation media via the network, instead of from a physical medium or an installation disk image. Refer to Book “Deployment Guide”, Chapter 18 “Preparing network boot environment” for more details about setting up a PXE boot environment.

To let your VM boot from a PXE server, follow these steps:

  1. Start the installation wizard as described in Section 10.1, “GUI-based guest installation”.

  2. Select the Manual Install method.

  3. Proceed to the last step of the wizard and activate Customize configuration before install. Confirm with Finish.

  4. On the Customize screen, select Boot Options.

  5. Inspect Boot device order and select Enable boot menu.

    • To retain VirtIO Disk as the default boot option, confirm with Apply.

    • To force the virtual machine to use PXE as the default boot option:

      1. Select the NIC device in the boot menu configuration.

      2. Move it to the top using the arrow signs on the right.

      3. Confirm with Apply.

  6. Start the installation by clicking Begin Installation. Now press Esc for boot menu and choose 1. iPXE. If a PXE server is properly configured, the PXE menu screen appears.

10.2 Installing from the command line with virt-install

  

virt-install is a command-line tool that helps you create new virtual machines using the libvirt library. It is useful if you cannot use the graphical user interface, or need to automatize the process of creating virtual machines.

virt-install is a complex script with a lot of command line switches. The following are required. For more information, see the man page of virt-install (1).

General options

  • --name VM_GUEST_NAME: Specify the name of the new virtual machine. The name must be unique across all guests known to the hypervisor on the same connection. It is used to create and name the guest’s configuration file and you can access the guest with this name from virsh. Alphanumeric and _-.:+ characters are allowed.

  • --memory REQUIRED_MEMORY: Specify the amount of memory to allocate for the new virtual machine in megabytes.

  • --vcpus NUMBER_OF_CPUS: Specify the number of virtual CPUs. For best performance, the number of virtual processors should be less than or equal to the number of physical processors.

Virtualization type

  • --paravirt: set up a paravirtualized guest. This is the default if the VM Host Server supports paravirtualization and full virtualization.

  • --hvm: set up a fully virtualized guest.

  • --virt-type HYPERVISOR: Specify the hypervisor. Supported values are kvm or xen.

Guest storage

Specify one of --disk, --filesystem or --nodisks the type of the storage for the new virtual machine. For example, --disk size=10 creates 10 GB disk in the default image location for the hypervisor and uses it for the VM Guest. --filesystem /export/path/on/vmhost specifies the directory on the VM Host Server to be exported to the guest. And --nodisks sets up a VM Guest without a local storage (good for Live CDs).

Installation method

Specify the installation method using one of --location, --cdrom, --pxe, --import, or --boot .

Accessing the installation

Use the --graphics VALUE option to specify how to access the installation. SUSE Linux Enterprise Server supports the values vnc or none.

If using VNC, virt-install tries to launch virt-viewer. If it is not installed or cannot be run, connect to the VM Guest manually with your preferred viewer. To explicitly prevent virt-install from launching the viewer, use --noautoconsole. To define a password for accessing the VNC session, use the following syntax: --graphics vnc,password=PASSWORD.

In case you are using --graphics none, you can access the VM Guest through operating system supported services, such as SSH or VNC. Refer to the operating system installation manual on how to set up these services in the installation system.

Passing kernel and initrd files

It is possible to directly specify the Kernel and Initrd of the installer, for example, from a network source. To set up a network source, see Book “Deployment Guide”, Chapter 17 “Setting up a network installation source”, Section 17.4 “Setting up an HTTP repository manually”.

To pass additional boot parameters, use the --extra-args option. This can be used to specify a network configuration. For details, see Book “Deployment Guide”, Chapter 8 “Boot parameters”.

Example 10.1: Loading kernel and initrd from HTTP server
  
# virt-install --location "http://example.tld/REPOSITORY/DVD1/" \
--extra-args="textmode=1" --name "SLES15" --memory 2048 --virt-type kvm\
--connect qemu:///system --disk size=10 --graphics vnc \
--network network=vnet_nated
Enabling the console

By default, the console is not enabled for new virtual machines installed using virt-install. To enable it, use --extra-args="console=ttyS0 textmode=1" as in the following example: 

> virt-install --virt-type kvm --name sles12 --memory 1024 \
 --disk /var/lib/libvirt/images/disk1.qcow2 --os-variant sles12
 --extra-args="console=ttyS0 textmode=1" --graphics none

After the installation finishes, the /etc/default/grub file in the VM image is updated with the console=ttyS0 option on the GRUB_CMDLINE_LINUX_DEFAULT line.

Using UEFI Secure Boot
Note
Note

SUSE supports UEFI Secure Boot on AMD64/Intel 64 KVM guests only. Xen HVM guests support booting with UEFI firmware, but they do not support UEFI Secure Boot.

By default, new virtual machines installed using virt-install are configured with a legacy BIOS. They can be configured to use UEFI with --boot firmware=efi. A firmware that supports UEFI Secure Boot and has Microsoft keys enrolled will be selected. If secure boot is undesirable, the option --boot firmware=efi,firmware.feature0.name=secure-boot,firmware.feature0.enabled=no can be used to select a UEFI firmware without secure boot support.

It is also possible to explicitly specify a UEFI firmware image. See Section 10.3.1, “Advanced UEFI configuration” for advanced information and examples on using UEFI with virtual machines.

Example 10.2: Example of a virt-install command line
  

The following command line example creates a new SUSE Linux Enterprise 15 SP2 virtual machine with a virtio accelerated disk and network card. It creates a new 10 GB qcow2 disk image as a storage, the source installation media being the host CD-ROM drive. It uses VNC graphics, and it automatically launches the graphical client.

KVM
> virt-install --connect qemu:///system --virt-type kvm \
--name sle15sp2 --memory 1024 --disk size=10 --cdrom /dev/cdrom --graphics vnc \
--os-variant sle15sp2
Xen
> virt-install --connect xen:// --virt-type xen --hvm \
--name sle15sp2 --memory 1024 --disk size=10 --cdrom /dev/cdrom --graphics vnc \
--os-variant sle15sp2

10.3 Advanced guest installation scenarios

  

This section provides instructions for operations exceeding the scope of a normal installation, such as manually configuring UEFI firmware, memory ballooning and installing add-on products.

10.3.1 Advanced UEFI configuration

  

The UEFI firmware used by virtual machines is provided by OVMF (Open Virtual Machine Firmware). The qemu-ovmf-x86_64 package contains firmwares for AMD64/Intel 64 VM Guests. Firmwares for AArch64 VM Guests are provided by the qemu-uefi-aarch64 package. Both packages contain several firmwares, each supporting a different set of features and capabilities. The packages also include JSON firmware descriptor files, which describe the features and capabilities of individual firmwares.

libvirt supports two methods of selecting virtual machine UEFI firmware: automatic and manual. With automatic selection, libvirt will select a firmware based on an optional set of features specified by the user. If no explicit features are specified, libvirt will select a firmware with secure boot enabled and Microsoft keys enrolled. When using manual selection, the full path of the firmware and any optional settings must be explicitly specified. Users can reference the JSON descriptor files to find a firmware that satisfies their requirements.

Tip
Tip

The directory /usr/share/qemu/firmware contains all the JSON files used by libvirt. This file gives you detailed information about the firmwares, including the capabilities of the features.

When using virt-install, automatic firmware selection is enabled by specifying the firmware=efi parameter to the boot option, for example, --boot firmware=efi. The selection process can be influenced by requesting the presence or absence of firmware features. The following example illustrates automatic firmware selection with UEFI Secure Boot disabled. 

> virt-install --connect qemu:///system --virt-type kvm \
--name sle15sp5 --memory 1024 --disk size=10 --cdrom /dev/cdrom --graphics vnc \
--boot firmware=efi,firmware.feature0.name=secure-boot,firmware.feature0.enabled=no \
--os-variant sle15sp5
Note
Note

To ensure persistent VM Guests use the same firmware and variable store throughout their lifetime, libvirt will record automatically selected firmware in the VM Guest XML configuration. Automatic firmware selection is a one-time activity. Once firmware has been selected, it will only change if the VM Guest administrator explicitly does so using the manual firmware selection method.

The loader and nvram parameters are used for manual firmware selection. loader is required, and nvram defines an optional UEFI variable store. The following example illustrates manual firmware selection with secure boot enabled. 

> virt-install --connect qemu:///system --virt-type kvm \
--name sle15sp5 --memory 1024 --disk size=10 --cdrom /dev/cdrom --graphics vnc \
--boot loader=/usr/share/qemu/ovmf-x86_64-smm-code.bin,loader.readonly=yes,loader.type=pflash,loader.secure=yes,nvram.template=/usr/share/qemu/ovmf-x86_64-smm-vars.bin \
--os-variant sle15sp5
Note
Note

libvirt cannot modify any characteristics of the UEFI firmwares. For example, it cannot disable UEFI Secure Boot in a firmware that has UEFI Secure Boot enabled, even when specifying loader.secure=no. libvirt will ensure the specified firmware can satisfy any specified features. For example, it will reject configuration that disables secure boot with loader.secure=no, but specifies a firmware that has UEFI Secure Boot enabled.

The qemu-ovmf-x86_64 package contains several UEFI firmware images. For example, the following subset supports SMM, UEFI Secure Boot, and has either Microsoft, openSUSE or SUSE UEFI CA keys enrolled: 

# rpm -ql qemu-ovmf-x86_64
[...]
/usr/share/qemu/ovmf-x86_64-smm-ms-code.bin
/usr/share/qemu/ovmf-x86_64-smm-ms-vars.bin
/usr/share/qemu/ovmf-x86_64-smm-opensuse-code.bin
/usr/share/qemu/ovmf-x86_64-smm-opensuse-vars.bin
/usr/share/qemu/ovmf-x86_64-smm-suse-code.bin
/usr/share/qemu/ovmf-x86_64-smm-suse-vars.bin
[...]

For the AArch64 architecture, the package is named qemu-uefi-aarch32: 

# rpm -ql qemu-uefi-aarch32
[...]
/usr/share/qemu/aavmf-aarch32-code.bin
/usr/share/qemu/aavmf-aarch32-vars.bin
/usr/share/qemu/firmware
/usr/share/qemu/firmware/60-aavmf-aarch32.json
/usr/share/qemu/qemu-uefi-aarch32.bin

The *-code.bin files are the UEFI firmware files. The *-vars.bin files are corresponding variable store images that can be used as a template for a per-VM non-volatile store. libvirt copies the specified vars template to a per-VM path under /var/lib/libvirt/qemu/nvram/ when first creating the VM. Files without code or vars in the name can be used as a single UEFI image. They are not as useful, since no UEFI variables persist across power cycles of the VM.

The *-ms*.bin files contain UEFI CA keys as found on real hardware. Therefore, they are configured as the default in libvirt. Likewise, the *-suse*.bin files contain preinstalled SUSE keys. There is also a set of files with no preinstalled keys.

For more details on OVMF, see http://www.linux-kvm.org/downloads/lersek/ovmf-whitepaper-c770f8c.txt.

10.3.2 Memory ballooning with Windows guests

  

Memory ballooning is a method to change the amount of memory used by VM Guest at runtime. Both the KVM and Xen hypervisors provide this method, but it needs to be supported by the guest as well.

While openSUSE and SLE-based guests support memory ballooning, Windows guests need the Virtual Machine Driver Pack (VMDP) to provide ballooning. To set the maximum memory greater than the initial memory configured for Windows guests, follow these steps:

  1. Install the Windows guest with the maximum memory equal or less than the initial value.

  2. Install the Virtual Machine Driver Pack in the Windows guest to provide required drivers.

  3. Shut down the Windows guest.

  4. Reset the maximum memory of the Windows guest to the required value.

  5. Start the Windows guest again.

10.3.3 Including add-on products in the installation

  

Certain operating systems, such as SUSE Linux Enterprise Server, offer to include add-on products in the installation process. If the add-on product installation source is provided via SUSE Customer Center, no special VM Guest configuration is needed. If it is provided via CD/DVD or ISO image, it is necessary to provide the VM Guest installation system with both the standard installation medium image and the image of the add-on product.

If you are using the GUI-based installation, select Customize Configuration Before Install in the last step of the wizard and add the add-on product ISO image via Add Hardware › Storage. Specify the path to the image and set the Device Type to CD-ROM.

If you are installing from the command line, you need to set up the virtual CD/DVD drives with the --disk parameter rather than with --cdrom. The device that is specified first is used for booting. The following example installs SUSE Linux Enterprise Server 15 together with SUSE Enterprise Storage extension: 

> virt-install \
 --name sles15+storage \
 --memory 2048 --disk size=10 \
 --disk /path/to/SLE-15-SP6-Full-ARCH-GM-media1.iso-x86_64-GM-DVD1.iso,device=cdrom \
 --disk /path/to/SUSE-Enterprise-Storage-VERSION-DVD-ARCH-Media1.iso,device=cdrom \
 --graphics vnc --os-variant sle15