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5.3. Creating guests with virt-manager

virt-manager, also known as Virtual Machine Manager, is a graphical tool for creating and managing virtualized guests.
Procedure 5.1. Creating a virtualized guest with virt-manager
  1. Open virt-manager

    Start virt-manager. Launch the Virtual Machine Manager application from the Applications menu and System Tools submenu. Alternatively, run the virt-manager command as root.
  2. Optional: Open a remote hypervisor

    Open the File -> Add Connection. The dialog box below appears. Select a hypervisor and click the Connect button:
  3. Create a new guest

    The virt-manager window allows you to create a new virtual machine. Click the New button to create a new guest. This opens the wizard shown in the screenshot.
  4. New guest wizard

    The Create a new virtual machine window provides a summary of the information you must provide in order to create a virtual machine:
    Review the information for your installation and click the Forward button.
  5. Name the virtual machine

    The following characters are allowed in guest names: '_', '.' and '-' characters.
    Press Forward to continue.
  6. Choose virtualization method

    The Choosing a virtualization method window appears.
    Full virtualization requires a processor with the AMD 64 and the AMD-V extensions or a processor with the Intel 64 and Intel VT extensions. If the virtualization extensions are not present, KVM will not be avilable.
    Choose the virtualization type and click the Forward button.
  7. Select the installation method

    The Installation Method window asks for the type of installation you selected.
    Guests can be installed using one of the following methods:
    Local media installation
    This method uses a CD-ROM or DVD or an image of an installation CD-ROM or DVD (an .iso file).
    Network installation tree
    This method uses a mirrored Fedora installation tree to install guests. The installation tree must be accessible using one of the following network protocols: HTTP, FTP or NFS.
    The network services and files can be hosted using network services on the host or another mirror.
    Network boot
    This method uses a Preboot eXecution Environment (PXE) server to install the guest. Setting up a PXE server is covered in the Fedora Deployment Guide. Using this method requires a guest with a routable IP address or shared network device. Refer to Chapter 11, Network Configuration for information on the required networking configuration for PXE installation.
    Set the OS type and OS variant.
    Choose the installation method and click Forward to procede.
  8. Installation media selection

    This window is dependent on what was selected in the previous step.
    1. ISO image or phyiscal media installation

      If Local install media was selected in the previous step this screen is called Install Media.
      Select the location of an ISO image or select a DVD or CD-ROM from the dropdown list.
      Click the Forward button to procede.
    2. Network install tree installation

      If Network install tree was selected in the previous step this screen is called Installation Source.
      Network installation requires the address of a mirror of a Linux installation tree using NFS, FTP or HTTP. Optionally, a kickstart file can be specified to automated the installation. Kernel parameters can also be specified if required.
      Click the Forward button to procede.
    3. Network boot (PXE)

      PXE installation does not have an additional step.
  9. Storage setup

    The Storage window displays. Choose a disk partition, LUN or create a file-based image for the guest storage.
    All image files should be stored in the /var/lib/libvirt/images/ directory. Other directory locations for file-based images are prohibited by SELinux. If you run SELinux in enforcing mode, refer to Section 19.2, “SELinux and virtualization” for more information on installing guests.
    Your guest storage image should be larger than the size of the installation, any additional packages and applications, and the size of the guests swap file. The installation process will choose the size of the guest's swap based on size of the RAM allocated to the guest.
    Allocate extra space if the guest needs additional space for applications or other data. For example, web servers require additional space for log files.
    Choose the appropriate size for the guest on your selected storage type and click the Forward button.


    It is recommend that you use the default directory for virtual machine images, /var/lib/libvirt/images/. If you are using a different location (such as /images/ in this example) make sure it is added to your SELinux policy and relabeled before you continue with the installation (later in the document you will find information on how to modify your SELinux policy).
  10. Network setup

    Select either Virtual network or Shared physical device.
    The virtual network option uses Network Address Translation (NAT) to share the default network device with the virtualized guest. Use the virtual network option for wireless networks.
    The shared physical device option uses a network bond to give the virtualized guest full access to a network device.
    Press Forward to continue.
  11. Memory and CPU allocation

    The Memory and CPU Allocation window displays. Choose appropriate values for the virtualized CPUs and RAM allocation. These values affect the host's and guest's performance.
    Guests require sufficient physical memory (RAM) to run efficiently and effectively. Choose a memory value which suits your guest operating system and application requirements. Most operating system require at least 512MB of RAM to work responsively. Remember, guests use physical RAM. Running too many guests or leaving insufficient memory for the host system results in significant usage of virtual memory. Virtual memory is significantly slower causing degraded system performance and responsiveness. Ensure to allocate sufficient memory for all guests and the host to operate effectively.
    Assign sufficient virtual CPUs for the virtualized guest. If the guest runs a multithreaded application, assign the number of virtualized CPUs the guest will require to run efficiently. Do not assign more virtual CPUs than there are physical processors (or hyper-threads) available on the host system. It is possible to over allocate virtual processors, however, over allocating has a significant, negative affect on guest and host performance due to processor context switching overheads.
    Press Forward to continue.
  12. Verify and start guest installation

    The Finish Virtual MAchine Creation window presents a summary of all configuration information you entered. Review the information presented and use the Back button to make changes, if necessary. Once you are satisfied click the Finish button and to start the installation process.
    A VNC window opens showing the start of the guest operating system installation process.
This concludes the general process for creating guests with virt-manager. Chapter 5, Virtualized guest installation overview contains step-by-step instructions to installing a variety of common operating systems.