Procedure 8.1. Creating a para-virtualized Red Hat Enterprise Linux 6 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. Select the hypervisor

   Select the hypervisor. Note that presently the KVM hypervisor is named qemu.
   Connect to a hypervisor if you have not already done so. Open the File menu and select the Add Connection... option. Refer to Section 31.5, “Adding a remote connection”.
   Once a hypervisor connection is selected the New button becomes available. Press the New button.

3. Start the new virtual machine wizard

   Pressing the New button starts the virtual machine creation wizard.

   

   Press Forward to continue.

4. Name the virtual machine

   Provide a name for your virtualized guest. The following punctuation and whitespace characters are permitted for '_', '.' and '-' characters.

   

   Press Forward to continue.

5. Choose a virtualization method

   Select Xen para-virtualized as the virtualization method.
   
   Press Forward to continue.

6. Select the installation method

   Red Hat Enterprise Linux can be installed using one of the following methods:
   • local install media, either an ISO image or physical optical media.
   • Select Network install tree if you have the installation tree for Red Hat Enterprise Linux hosted somewhere on your network via HTTP, FTP or NFS.
   • PXE can be used if you have a PXE server configured for booting Red Hat Enterprise Linux installation media. Configuring a sever to PXE boot a Red Hat Enterprise Linux installation is not covered by this guide. However, most of the installation steps are the same after the media boots.
   Set OS Type to Linux and OS Variant to Red Hat Enterprise Linux 5 as shown in the screenshot.

   

   Press Forward to continue.

7. Locate installation media

   Select ISO image location or CD-ROM or DVD device. This example uses an ISO file image of the Red Hat Enterprise Linux installation DVD.
   1. Press the Browse button.
   2. Search to the location of the ISO file and select the ISO image. Press Open to confirm your selection.
   3. The file is selected and ready to install.

      

      Press Forward to continue.

   Image files and SELinux

   For ISO image files and guest storage images it is recommended to use the /var/lib/libvirt/images/ directory. Any other location may require additional configuration for SELinux, refer to Section 16.2, “SELinux and virtualization” for details.

8. Storage setup

   Assign a physical storage device (Block device) or a file-based image (File). File-based images should be stored in the /var/lib/libvirt/images/ directory to satisfy default SELinux permissions. Assign sufficient space for your virtualized guest and any applications the guest requires.

   

   Press Forward to continue.

   Migration

   Live and offline migrations require guests to be installed on shared network storage. For information on setting up shared storage for guests refer to Part V, “Virtualization storage topics”.

9. 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.

10. 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.
    Virtualized guests require sufficient physical memory (RAM) to run efficiently and effectively. Choose a memory value which suits your guest operating system and application requirements. Remember, guests use physical RAM. Running too many guests or leaving insufficient memory for the host system results in significant usage of virtual memory and swapping. Virtual memory is significantly slower which causes degraded system performance and responsiveness. Ensure you 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 effect on guest and host performance due to processor context switching overheads.
    

    Press Forward to continue.

11. Verify and start guest installation

    Verify the configuration.

    

    Press Finish to start the guest installation procedure.

12. Installing Red Hat Enterprise Linux

    Complete the Red Hat Enterprise Linux installation sequence. The installation sequence is covered by the Red Hat Enterprise Linux 6 Installation Guide. Refer to Red Hat Documentation for the Red Hat Enterprise Linux 6 Installation Guide.