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<chapter id="chap-Virtualization_Getting_Started-Products">
	<title>Introduction to Fedora virtualization products</title>
	<para>This chapter introduces the various virtualization products available in Fedora.</para>
<section id="sec-kvm_and_virt">
	<title>KVM and virtualization in Fedora</title>
	<variablelist>
               <varlistentry>
                        <term>What is KVM?</term>
                        <listitem>
                              <para>
                                 KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel&nbsp;64 hardware that is built into the standard Fedora kernel. It can run multiple, unmodified Windows and Linux guest operating systems. The KVM hypervisor in Fedora is managed with the <application>libvirt</application> API and tools built for <application>libvirt</application> (such as <command>virt-manager</command> and <command>virsh</command>). Virtual machines are executed and run as multi-threaded Linux processes controlled by these tools.
                              </para>
                        </listitem>
               </varlistentry>
               <varlistentry>
                        <term>Overcommitting</term>
                        <listitem>
                              <para>
                                 KVM hypervisor supports <firstterm>overcommitting</firstterm> of system resources. Overcommitting means allocating more virtualized CPUs or memory than the available resources on the system. Memory overcommitting allows hosts to utilize memory and virtual memory to increase guest densities.
                              </para>
                              <important>
                                    <para>
                                       Overcommitting involves possible risks to system stability. For more information on overcommitting with KVM, and the precautions that should be taken, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                                    </para>
                              </important>
                        </listitem>
               </varlistentry>
               <varlistentry>
                        <term>Thin provisioning</term>
                        <listitem>
                                 <para>
                                       Thin provisioning allows the allocation of flexible storage and optimizes the available space for every guest. It gives the appearance that there is more physical storage on the guest than is actually available. This is not the same as overcommitting as this only pertains to storage and not CPUs or memory allocations. However, like overcommitting, the same warning applies.
                                 </para>
                                 <important>
                                       <para>
                                          Thin provisioning involves possible risks to system stability. <!--For more information on thin provisioning with KVM, and the precautions that should be taken, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.-->
                                       </para>
                                 </important>        
                        </listitem>
               </varlistentry>
               <varlistentry>
                        <term>KSM</term>
                        <listitem>
                                 <para>
                                       <firstterm>Kernel SamePage Merging (KSM)</firstterm>, used by the KVM hypervisor, allows KVM guests to share identical memory pages. These shared pages are usually common libraries or other identical, high-use data. KSM allows for greater guest density of identical or similar guest operating systems by avoiding memory duplication.
                                 </para>
                                <note>
                                       <para>
                                             For more information on KSM, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                                       </para>
                                 </note>
                        </listitem>
               </varlistentry>
               <varlistentry><!--Added to RHEL 6.4, adding for F19-->
                        <term>QEMU guest agent</term>
                        <listitem>
                                 <para>
                                       The <firstterm>QEMU guest agent</firstterm> runs on the guest operating system and allows the host machine to issue commands to the guest operating system.
                                 </para>
                                <note> 
                                       <para>
                                             For more information on the QEMU guest agent, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                                       </para>
                                 </note>
                        </listitem>
               </varlistentry>
               <varlistentry>
                        <term>KVM guest virtual machine compatibility</term>
                        <listitem>
                                 <para>
                                       To verify whether your processor supports the virtualization extensions and for information on enabling the virtualization extensions if they are disabled, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide.</citetitle>
                                 </para>
         <!-- REMOVED AS THERE IS NO FEDORA SUPPORT MATRIX. <para>
        Fedora servers have certain support limits.
        </para>
        <para> Is there a corresponding matrix for Fedora?
        The following URLs explain the processor and memory amount limitations for Red Hat Enterprise Linux:
        </para>
        <itemizedlist>
                <listitem>
                        <para>For host systems: <ulink url="http://www.redhat.com/products/enterprise-linux/server/compare.html">http://www.redhat.com/products/enterprise-linux/server/compare.html</ulink></para>
                </listitem>
                <listitem>
                        <para>For hypervisors: <ulink url="http://www.redhat.com/resourcelibrary/articles/virtualization-limits-rhel-hypervisors">http://www.redhat.com/resourcelibrary/articles/virtualization-limits-rhel-hypervisors</ulink></para>
                </listitem>
        </itemizedlist>
        <para>
                For a complete chart of supported operating systems and host and guest combinations refer to<ulink url="http://www.redhat.com/resourcelibrary/articles/enterprise-linux-virtualization-support"> http://www.redhat.com/resourcelibrary/articles/enterprise-linux-virtualization-support</ulink>.
        </para>-->
                        </listitem>
               </varlistentry>               
         </variablelist>
</section>
<section id="sec_libvirt-libvirt-tools">
	<title>libvirt and libvirt tools</title>
	<para>
           The <package>libvirt</package> package is a hypervisor-independent virtualization API that is able to interact with the virtualization capabilities of a range of operating systems.
        </para>
	<para>
           The <package>libvirt</package> package provides:
        </para>
	<itemizedlist>
		<listitem>
			<para>
                           A common, generic, and stable layer to securely manage virtual machines on a host.
			</para>
		</listitem>
		<listitem>
			<para>
                           A common interface for managing local systems and networked hosts.
			</para>
		</listitem>
		<listitem>
                        <para>
                           All of the APIs required to provision, create, modify, monitor, control, migrate, and stop virtual machines, but only if the hypervisor supports these operations. Although multiple hosts may be accessed with <application>libvirt</application> simultaneously, the APIs are limited to single node operations.
                        </para>
		</listitem>
	</itemizedlist>	
	<para>
           The <package>libvirt</package> package is designed as a building block for higher level management tools and applications, for example, <command>virt-manager</command> and the <command>virsh</command> command-line management tools. With the exception of migration capabilities, <application>libvirt</application> focuses on managing single hosts and provides APIs to enumerate, monitor and use the resources available on the managed node, including CPUs, memory, storage, networking and Non-Uniform Memory Access (NUMA) partitions. The management tools can be located on separate physical machines from the host using secure protocols. <application>libvirt</application> is the the foundation of the Gnome application: <application>gnome-boxes</application> is built apon.
        </para>
        <para>
           Fedora supports <application>libvirt</application> and included <application>libvirt</application>-based tools as its default method for virtualization management.
        </para>
        <para>
           The <package>libvirt</package> package is available as free software under the GNU Lesser General Public License. The <package>libvirt</package> project aims to provide a long term stable C API to virtualization management tools, running on top of varying hypervisor technologies. <!--The <package>libvirt</package> package supports Xen on Red Hat Enterprise Linux&nbsp;5, and it supports KVM on both Red Hat Enterprise Linux&nbsp;5 and Red Hat Enterprise Linux&nbsp;6.-->
        </para>
        <variablelist>
               <varlistentry>
                        <term>virsh</term>
                        <listitem>
                              <para>
				The <command>virsh</command> command-line tool is built on the <application>libvirt</application> management API and operates as an alternative to the graphical <command>virt-manager</command> application. The <command>virsh</command> command can be used in read-only mode by unprivileged users or, with root access, full administration functionality. The <command>virsh</command> command is ideal for scripting virtualization administration.
                              </para>
                        </listitem>
               </varlistentry>
               <varlistentry>
                        <term>virt-manager</term>
                        <listitem>
                              <para>
				<command>virt-manager</command> is a graphical desktop tool for managing virtual machines. It allows access to graphical guest consoles and can be used to perform virtualization administration, virtual machine creation, migration, and configuration tasks. The ability to view virtual machines, host statistics, device information and performance graphs is also provided. The local hypervisor and remote hypervisors can be managed through a single interface.
                              </para>
                        </listitem>
               </varlistentry>
            </variablelist>
               <note>
                     <para>
                        For more information on <command>virsh</command> and <application>virt-manager</application>, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                     </para>
                  </note>
</section>
<section id="sec-virtualized-hardware-devices">
            <title>Virtualized hardware devices</title>
            <para>
               Virtualization on Fedora presents three distinct types of system devices to virtual machines. The three types include:
                              <!-- Revisit this with the PCI device assignment definitions for RHEL 6.5 and 7. Redfine? -->
            </para>
               <itemizedlist>
                     <listitem>
                              <para>
                                 Virtualized and emulated devices
                              </para>
                     </listitem>
                     <listitem>
                              <para>
                                 Para-virtualized devices
                              </para>
                     </listitem>
                     <listitem>
                              <para>
                                 Physically shared devices
                              </para>
                     </listitem>
               </itemizedlist>
            <para>These hardware devices all appear as being physically attached to the virtual machine but the device drivers work in different ways.</para>
                <section id="sec-virt-emulated-devices">
                        <title>Virtualized and emulated devices</title>
                        <para>
                           KVM implements many core devices <!--devices and drivers?--> for virtual machines in software. These emulated hardware devices are crucial for virtualizing operating systems.
                        </para>
                        <para>
                           Emulated devices are virtual devices which exist entirely in software.
                        </para>
                        <para>
                           Emulated drivers may use either a physical device or a virtual software device. Emulated drivers are a translation layer between the virtual machine and the Linux kernel (which manages the source device). The device level instructions are completely translated by the KVM hypervisor. Any device, of the same type (storage, network, keyboard, and mouse) and recognized by the Linux kernel, may be used as the backing source device for the emulated drivers.
                        </para>
                        <variablelist>
                           <varlistentry>
                              <term>Virtual CPUs (vCPUs)</term>
                              <listitem>
                                    <para>                      
                                       A host system can have up to 160 virtual CPUs (vCPUs) that can be presented to guests for their use, regardless of the number of host CPUs. 
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>Emulated graphics devices</term>
                              <listitem>
                                    <para>
                                       Two emulated graphics devices are provided. These devices can be connected to with the SPICE (Simple Protocol for Independent Computing Environments) protocol or with VNC:
                                    </para>
                                    <itemizedlist>
                                          <listitem>
                                                   <para>A Cirrus CLGD 5446 PCI VGA card (using the <emphasis>cirrus</emphasis> device)</para>
                                          </listitem>
                                          <listitem>
                                                   <para>A standard VGA graphics card with Bochs VESA extensions (hardware level, including all non-standard modes)</para>
                                          </listitem>
                                    </itemizedlist>
                             </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>Emulated system components</term>
                              <listitem>
                                    <para>                      
                                       The following core system components are emulated to provide basic system functions:
                                    </para>
                                    <itemizedlist>
                                          <listitem>
                                                   <para>Intel i440FX host PCI bridge</para>
                                          </listitem>
                                          <listitem>
                                                   <para>PIIX3 PCI to ISA bridge</para>
                                          </listitem>
                                          <listitem>
                                                   <para>PS/2 mouse and keyboard</para>
                                          </listitem>
                                          <listitem>
                                                   <para>EvTouch USB graphics tablet</para>
                                          </listitem>
                                          <listitem>
                                                   <para>PCI UHCI USB controller and a virtualized USB hub</para>
                                          </listitem>
                                          <listitem>
                                                   <para>Emulated serial ports</para>
                                          </listitem>
                                          <listitem>
                                             <para>EHCI controller, virtualized USB storage and a USB mouse</para>
                                          </listitem>
                                          <listitem> <!--for BZ952527 (RHEL7 and F19) - correct usage? IBM calls it USB 3.0 eXtensible Host Controller-->
                                             <para>USB 3.0 xHCI host controller</para>
                                          </listitem>                                          
                                    </itemizedlist>
                             </listitem>
                           </varlistentry>
                           <varlistentry> 
                              <term>Emulated sound devices</term>  <!--What is the Fedora equivalent for all of this?-->
                              <listitem>
                                    <para> <!--FIX THIS PART! VERIFY WITH SMEs - commented out '18'-->
                                       <!--Red Hat Enterprise Linux&nbsp;6.1 and above--> Fedora<!--&nbsp;18--> provides an emulated (Intel) HDA sound device, <systemitem>intel-hda</systemitem>. <!--This device is supported on the following guest operating systems:-->
                                    </para>
                                    <!--<itemizedlist>
                                          <listitem>
                                             <para>
                                                Red Hat Enterprise Linux 6, for i386 and x86_64 architectures
                                             </para>
                                          </listitem>
                                          <listitem>
                                             <para>
                                                Red Hat Enterprise Linux 5, for i386 and x86_64 architectures
                                             </para>
                                          </listitem>
                                          <listitem>
                                             <para>
                                                Red Hat Enterprise Linux 4, for i386 and x86_64 architectures
                                             </para>
                                          </listitem>
                                          <listitem>
                                             <para>
                                                Windows 7, for i386 and x86_64 architectures
                                             </para>
                                          </listitem>
                                          <listitem>
                                             <para>
                                                Windows 2008 R2, for the x86_64 architecture
                                             </para>
                                          </listitem>
                                    </itemizedlist>-->
                                    <para>
                                       The following two emulated sound devices are also available, but are not recommended due to compatibility issues with certain guest operating systems:
                                    </para>
                                    <itemizedlist>
                                          <listitem>
                                                   <para><systemitem>ac97</systemitem>, an emulated Intel 82801AA AC97 Audio compatible sound card</para>
                                          </listitem>
                                          <listitem>
                                                   <para><systemitem>es1370</systemitem>, an emulated ENSONIQ AudioPCI ES1370 sound card</para>
                                          </listitem>
                                    </itemizedlist>
                             </listitem>
                           </varlistentry>
                        
                           <varlistentry> 
                           <term>Emulated watchdog devices</term>                              <!-- Verify for Fedora with SMEs! Removed questionable bits for now. -->
                              <listitem>
                                    <para>
                                       <!--Red Hat Enterprise Linux&nbsp;6.0 and above--> Fedora<!--&nbsp;18--> provides two emulated watchdog devices. A watchdog can be used to automatically reboot a virtual machine when it becomes overloaded or unresponsive.
                                    </para>
                                    <para>
                                       The <package>watchdog</package> package must be installed on the guest. 
                                    </para>
                                    <para>
                                       The two devices available are:
                                    </para>
                                    <itemizedlist>
                                          <listitem>
                                             <para>
                                                <systemitem>i6300esb</systemitem>, an emulated Intel 6300 ESB PCI watchdog device. <!--It is supported in guest operating system Red Hat Enterprise Linux versions 6.0 and above, and is the recommended device to use.-->
                                             </para>
                                          </listitem>
                                          <listitem>
                                             <para>
                                                <systemitem>ib700</systemitem>, an emulated iBase 700 ISA watchdog device. <!--The <systemitem>ib700</systemitem> watchdog device is only supported in guests using Red Hat Enterprise Linux&nbsp;6.2 and above.-->
                                             </para>
                                          </listitem>
                                    </itemizedlist>
                                   <!-- <para>
                                       Both watchdog devices are supported in i386 and x86_64 architectures for guest operating systems Red Hat Enterprise Linux&nbsp;6.2 and above.
                                    </para>-->
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>Emulated network devices</term>
                              <listitem>
                                    <para>
                                       There are two emulated network devices available:
                                    </para>
                                    <itemizedlist>
                                          <listitem>
                                                   <para>The <systemitem>e1000</systemitem> device emulates an Intel E1000 network adapter (Intel 82540EM, 82573L, 82544GC).</para>
                                          </listitem>
                                          <listitem>
                                                   <para>The <systemitem>rtl8139</systemitem> device emulates a Realtek 8139 network adapter. </para>
                                          </listitem>
                                    </itemizedlist>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>Emulated storage drivers</term>
                              <listitem>
                                    <para>
                                       Storage devices and storage pools can use these emulated devices to attach storage devices to virtual machines. The guest uses an emulated storage driver to access the storage pool.
                                    </para>
                                    <para>
                                       Note that like all virtual devices, the storage drivers are not storage devices. The drivers are used to attach a backing storage device, file or storage pool volume to a virtual machine. The backing storage device can be any supported type of storage device, file, or storage pool volume.
                                    </para>
                                             <variablelist>
                                                   <varlistentry>
                                                            <term>The emulated IDE driver</term>
                                                            <listitem>
                                                                  <para>
                                                                     KVM provides two emulated PCI IDE interfaces. An emulated IDE driver can be used to attach any combination of up to four virtualized IDE hard disks or virtualized IDE CD-ROM drives to each virtual machine. The emulated IDE driver is also used for virtualized CD-ROM and DVD-ROM drives.
                                                                  </para>
                                                            </listitem>
                                                   </varlistentry>
                                                   <varlistentry>
                                                            <term>The emulated floppy disk drive driver</term>
                                                            <listitem>
                                                                  <para>
                                                                     The emulated floppy disk drive driver is used for creating virtualized floppy drives.
                                                                  </para>
                                                            </listitem>
                                                   </varlistentry>
                                             </variablelist>
                              </listitem>
                           </varlistentry>
                        </variablelist>                                 
                </section>
                <section id="para-virtdevices">
                        <title>Para-virtualized devices</title> 
                        <para>
                              Para-virtualized devices are drivers for virtual devices that increase the I/O performance of virtual machines. 
                        </para>
                        <para>
                              Para-virtualized devices decrease I/O latency and increase I/O throughput to near bare-metal levels. It is recommended to use the para-virtualized device drivers for virtual machines running I/O intensive applications.
                        </para>
                        <para>
                           The para-virtualized devices must be installed on the guest operating system. The para-virtualized device drivers must be manually installed on Windows guests.
                        </para>
                        <note>
                              <para>
                                 For more information on using the para-virtualized drivers, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                              </para>
                        </note>
                        <variablelist>
                           <varlistentry>
                              <term>The para-virtualized network driver (virtio-net)</term>
                              <listitem>
                                    <para>
                                       The para-virtualized network driver <!--is a Red Hat branded virtual network device. It--> can be used as the driver for existing network devices or new network devices for virtual machines.
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The para-virtualized block driver (virtio-blk)</term>
                              <listitem>
                                    <para>
                                       The para-virtualized block driver is a driver for all storage devices, is supported  by the hypervisor, and is attached to the virtual machine (except for floppy disk drives, which must be emulated).
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The para-virtualized controller device (virtio-scsi)</term>
                              <listitem>
                                    <para>
                                      The para-virtualized SCSI controller device provides a more flexible and scalable alternative to virtio-blk. A virtio-scsi guest is capable of inheriting the feature set of the target device, and can handle hundreds of devices compared to virtio-blk, which can only handle 28 devices.
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The para-virtualized clock</term>
                              <listitem>
                                    <para>
                                       Guests using the Time Stamp Counter (TSC) as a clock source may suffer timing issues. KVM works around hosts that do not have a constant Time Stamp Counter by providing guests with a para-virtualized clock.
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The para-virtualized serial driver (virtio-serial)</term>
                              <listitem>
                                    <para>
                                       The para-virtualized serial driver is a bytestream-oriented, character stream driver, and provides a simple communication interface between the host's user space and the guest's user space.
                                    </para>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The balloon driver (virtio-balloon)</term>
                              <listitem>
                                    <para>
                                       The balloon driver can designate part of a virtual machine's RAM as not being used (a process known as balloon <emphasis>inflation</emphasis>), so that the memory can be freed for the host (or for other virtual machines on that host) to use. When the virtual machine needs the memory again, the balloon can be <emphasis>deflated</emphasis> and the host can distribute the RAM back to the virtual machine.
                                    </para>
                             </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>The para-virtualized random number generator (virtio-rng)</term>
                              <listitem>
                                    <para>
                                          The para-virtualized random number generator enables virtual machines to collect entropy, or randomness, directly from the host to use for encrypted data and security. Virtual machines can often be starved of entropy because typical inputs (such as hardware usage) are unavailable. Sourcing entropy can be time-consuming; virtio-rng makes this process faster by injecting entropy directly into guest virtual machines from the host.
                                    </para>
                             </listitem>
                           </varlistentry>
                        </variablelist>                         
                </section>
                <section>
                        <title>Physical host devices</title>
                        <para>
                           Certain hardware platforms allow virtual machines to directly access various hardware devices and components. This process in virtualization is known as <firstterm>device assignment</firstterm>. Device assignment is also known as <firstterm>passthrough</firstterm>.
                        </para>
                        <variablelist>
                           <varlistentry>
                              <term>PCI device assignment</term>
                              <listitem>
                                    <para>
                                       The KVM hypervisor supports attaching PCI devices on the host system to virtual machines. PCI device assignment allows guests to have exclusive access to PCI devices for a range of tasks. It allows PCI devices to appear and behave as if they were physically attached to the guest virtual machine.
                                    </para>
                                    <para>
                                       Device assignment is supported on PCI Express devices, with the exception of graphics cards. Parallel PCI devices may be supported as assigned devices, but they have severe limitations due to security and system configuration conflicts.
                                    </para>
                                       <note>
                                          <para>
                                             For more information on device assignment, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                                          </para>
                                       </note> 
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>USB passthrough</term>
                              <listitem>
                                    <para>
                                       The KVM hypervisor supports attaching USB devices on the host system to virtual machines. USB device assignment allows guests to have exclusive access to USB devices for a range of tasks. It allows USB devices to appear and behave as if they were physically attached to the virtual machine.
                                    </para>
<!--                                       <note>
                                          <para>
                                             For more information on USB passthrough, refer to the <citetitle>Fedora Virtualization Administration Guide</citetitle>.
                                          </para>
                                       </note>-->
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>SR-IOV</term>
                              <listitem>
                                    <para>
                                       SR-IOV (Single Root I/O Virtualization) is a PCI Express standard that extends a single physical PCI function to share its PCI resources as separate, virtual functions (VFs). Each function is capable of being used by a different virtual machine via PCI device assignment. 
                                    </para>
                                    <para>
                                       An SR-IOV capable PCI-e device, provides a Single Root Function (for example, a single Ethernet port) and presents multiple, separate virtual devices as unique PCI device functions. Each virtual device may have its own unique PCI configuration space, memory-mapped registers, and individual MSI-based interrupts.
                                    </para> 
                                      <note>
                                          <para>
                                             For more information on SR-IOV, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
                                          </para>
                                       </note>
                              </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>NPIV</term>
                              <listitem>
                                    <para>
                                       N_Port ID Virtualization (NPIV) is a functionality available with some Fibre Channel devices. NPIV shares a single physical N_Port as multiple N_Port IDs. NPIV provides similar functionality for Fibre Channel Host Bus Adapters (HBAs) that SR-IOV provides for PCIe interfaces. With NPIV, virtual machines can be provided with a virtual Fibre Channel initiator to Storage Area Networks (SANs).
                                    </para>
                                    <para>
                                       NPIV can provide high density virtualized environments with enterprise-level storage solutions.
                                    </para>
<!--                                       <note>
                                          <para>
                                             For more information on NPIV, refer to the <citetitle>Fedora Virtualization Administration Guide</citetitle>.
                                          </para>
                                       </note>-->
                              </listitem>
                           </varlistentry>
                        </variablelist>
 
</section>
<section id="para-CPU_Models">
        <title>CPU models</title>
         <para>
            CPU models define which host CPU features are available to
               the guest operating system. <application>qemu-kvm</application>
               and <application>libvirt</application> contain definitions for a
               number of current processor models, allowing users to enable 
               features that are available only in newer CPU models.
               The CPU feature set available to guests depends on
               support in the host CPU kernel. The <application>qemu-kvm</application>
               code must also allow the feature to be enabled.
            </para>
            <para>
               To safely migrate virtual machines between hosts with different CPU
               feature sets, <application>qemu-kvm</application> does not expose all CPU features
               from the host CPU to guest operating systems by default. Instead, CPU features are 
               exposed to virtual machines based on the chosen CPU model. 
            </para>
            <para>
               It is also possible to enable or disable specific CPU features in a virtual machine's
               XML configuration. However, it is safer to use predefined CPU models, as incorrect
               configuration can cause compatibility issues with the guest operating system.
            </para>
         <!--   WAS:
            Historically, CPU model definitions were hard-coded in 
            <application>qemu</application>. This method of defining CPU models was 
            inflexible, and made it difficult to create virtual CPUs with feature sets 
            that matched existing physical CPUs. Typically, users modified a basic CPU 
            model definition with feature flags in order to provide the CPU 
            characteristics required by a virtual machine. Unless these feature sets were carefully 
            controlled, safe migration &mdash; which requires feature sets between current and 
            prospective hosts to match &mdash; was difficult to support.
         </para>
         <para>
            <application>qemu-kvm</application> has now replaced most hard-wired definitions 
            with configuration file based CPU model definitions. Definitions for a number 
            of current processor models are now included by default, allowing users to specify 
            features more accurately and migrate more safely.
         </para>-->
            <note>
               <para>
                  For more information on CPU model availability and configuration, refer 
                  to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
               </para>
            </note>

            </section>
</section> 
<section id="Boxes">
<title>Boxes</title>
<para>
<application>Boxes</application> A simple graphical interface for virtual machines. 
</para>
<para>
Boxes uses <application>qemu-kvm</application>, <application>libvirt-glib</application> and <application>spice-gtk</application>to allow users to easily manage virtual machines and connect to remote machines
</para>
	<para>
	Features:
	</para>
	<itemizedlist>
		<listitem><para>View, access, and use: remote machines, remote and local virtual machines, and access for applications on virtual machines </para></listitem>
		<listitem><para>View, access, and use virtual machines on removable media </para></listitem>
		<listitem><para>View, access, and use shared connection / machines </para></listitem>
		<listitem><para>Upload / publish virtual machines </para></listitem>
		<listitem><para>Select favorites </para></listitem>		
		<listitem><para>Search for connections </para></listitem>
		</itemizedlist>
		<procedure><title>Create a Virtual Machine In Boxes</title>
<step>
 <para>
  Download an ISO image of an operating system that will be used in the virtual machine
 </para>
</step>our
<step>
 <para>
 Launch Boxes from the application launcher, super key, or terminal
 </para>
</step>
<step>
 <para>
 Click the New Button in the upper left hand corner
 </para>
</step>
<step>
 <para>
 Read the introduction and click continue in the upper right hand corner
 </para>
</step>
<step>
 <para>
 Select the ISO Image that was previously downloaded to the Downloads folder, otherwise click "select a file" to find one somewhere else
 </para>
</step>
<step>
 <para>
 Boxes will then auto create settings, they can be edited by clicking "customize"
 </para>
</step>
<step>
 <para>
 Memory and Disk allocation can be changed via the customize menu.
 </para>
</step>
<step>
 <para>
 Click Create
 </para>
</step>
<step>
 <para>
 The new virtual machine will now boot
 </para>
</step>
</procedure>
<note><para> Virtual machine settings can be changed by clicking on the <emphasis>screwdriver/wrench icon </emphasis> in the top Right hand side of the menu bar like:
</para>
<itemizedlist>
<listitem><para>Sharing the clipboard</para></listitem>
<listitem><para>Resize Guest</para></listitem>
<listitem><para>Redirect New USB Devices to the Virtual Machine</para></listitem>
<listitem><para>Redirect currently plugged in USB devices to the Virtual machine</para></listitem>
<listitem><para>Create Snapshots of the Virtual Machine from the snapshot heading</para></listitem>
<listitem><para>Force Shutdown, by clicking "Force Shutdown" in the lower left hand corner</para></listitem>
</itemizedlist>
<para> To exit the settings menu, <emphasis>press the arrow pointing "back" or to the left on the top left hand side of the menu bar</emphasis>. This will return you to your virtual machine console
</para></note>
</section>
<section id="sec-guestfish">
      <title>guestfish</title>
      <para>
         <firstterm>guestfish</firstterm> is a command line tool for examining and modifying the file systems of
         the host. This tool uses <package>libguestfs</package> and
         exposes all functionality provided by the <literal>guestfs</literal> API.
         This tool ships in its own package entitled <package>guestfish</package>.
      </para>
      <warning>
         <para>
            Using <command>guestfish</command> on running virtual machines can
            cause disk-image corruption. Use the <command>guestfish</command> command with the <option>--ro</option> (read-only)
            option if the disk image is being used by a running virtual machine.
         </para>
      </warning>
         <note>
            <para>
               Refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle> for more information about <command>guestfish</command>.
            </para>
         </note>
   </section>
<section id="sec-Storage">		
                <title>Storage</title>
                        <para>
                           Storage for virtual machines is abstracted from the physical storage used by the virtual machine. It is attached to the virtual machine using the para-virtualized or emulated block device drivers.
                        </para>
                <section>
                        <title>Storage pools</title>
                        <para>
                          A <firstterm>storage pool</firstterm> is a file, directory, or storage device managed by <application>libvirt</application> for the purpose of providing storage to virtual machines. Storage pools are divided into storage <firstterm>volumes</firstterm> that store virtual machine images or are attached to virtual machines as additional storage. Multiple guests can share the same storage pool, allowing for better allocation of storage resources.
                        </para>
                        <variablelist>
                           <varlistentry>
                              <term>Local storage pools</term>
                                <listitem>
                                    <para>
                                       Local storage pools are directly attached to the host server. They include local directories, directly attached disks, physical partitions, and LVM volume groups on local devices. Local storage pools are useful for development, testing and small deployments that do not require migration or large numbers of virtual machines. Local storage pools may not be suitable for many production environments as they do not support live migration.
                                    </para>
                                </listitem>
                           </varlistentry>
                           <varlistentry>
                              <term>Networked (shared) storage pools</term>
                                <listitem>
                                    <para>
                                       Networked storage pools include storage devices shared over a network using standard protocols. Networked storage is required when migrating virtual machines between hosts with <application>virt-manager</application>, but is optional when migrating with <command>virsh</command>. Networked storage pools are managed by <application>libvirt</application>.
                                    </para>
                                </listitem>
                           </varlistentry>
                        </variablelist>
                     </section>
                     <section>
                              <title>Storage volumes</title>
                                    <para>                      
                                       Storage pools are further divided into storage volumes. Storage volumes are an abstraction of physical partitions, LVM logical volumes, file-based disk images and other storage types handled by <application>libvirt</application>. Storage volumes are presented to virtual machines as local storage devices regardless of the underlying hardware.
                                    </para>

            <note>
               <para>
                  For more information on storage and virtualization, refer to the <citetitle>Fedora Virtualization Deployment and Administration Guide</citetitle>.
               </para>
            </note>
        </section>
</section>
<section id="sec-Other-Useful-tools">
      <title>Other useful tools</title>
      <para>The following tools are used to access a virtual machine's disk via the host. The guest's disk is usually accessed directly via the <filename>disk-image</filename> file located on the host. However it is sometimes possible to gain access via the <application>libvirt</application> domain. The commands that follow are part of the <application>libvirt</application> domain and are used to gain access to the guest's disk image.</para>

   <variablelist>
      <varlistentry>
       <term><command>guestmount</command></term>
       <listitem>
          <para>
            A command line tool used to mount virtual machine file systems and disk
           images on the host machine. This tool is installed as part of the <package>libguestfs-mount</package> package.
          </para>
          <warning>
             <para>
                Using <command>guestmount</command> in <option>--r/w</option> (read/write) mode to access a disk that is currently being used by a guest can cause the disk to become corrupted. Do not use <command>guestmount</command> in <option>--r/w</option> (read/write) mode on live virtual machines. Use the <command>guestmount</command> command with the <option>--ro</option> (read-only) option if the disk image is being used.
             </para>
          </warning>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-cat</command></term>
       <listitem>
          <para>
             A command line tool that can be used to quickly view the contents of 
             one or more files in a specified virtual machine's disk or disk image. This
             tool is installed as part of the <package>libguestfs-tools</package>
             package.
          </para>
       </listitem>
      </varlistentry>
      <!-- All released versions problematic; being rewritten upstream.
      <varlistentry>
       <term><command>virt-clone</command></term>
       <listitem>
          <para>
             Clone a VM.
          </para>
       </listitem>
      </varlistentry>-->
      <!-- This tool is obsolete and problematic.  Use virt-v2v instead.
      <varlistentry>
       <term><command>virt-convert</command></term>
       <listitem>
          <para>
             Convert a VM disk image.
          </para>
       </listitem>
      </varlistentry>-->
      <varlistentry>
       <term><command>virt-df</command></term>
       <listitem>
          <para>
             A command line tool used to show the actual physical disk usage of 
             virtual machines. Similar to the command line tool <command>df</command>.
             Note that this tool does not work across remote connections. It is
             installed as part of the <package>libguestfs-tools</package> package.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-edit</command></term>
       <listitem>
          <para>
            A command line tool used to edit files that exist on a specified virtual
            machine. This tool is installed as part of the 
            <package>libguestfs-tools</package> package.
          </para>
        <warning>
             <para>
                Using <command>virt-edit</command> on live virtual machines can
                cause disk corruption in the virtual machine. 
                Although the <command>virt-edit</command> command will try to prevent users from editing
                files on live virtual machines, it is not guaranteed to catch all instances.
                Do not use <command>virt-edit</command> on a live virtual machine.
             </para>
          </warning>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-filesystems</command></term>
       <listitem>
         <para>
            A command line tool used to discover file systems, partitions, logical
            volumes and their sizes in a disk image or virtual machine. One common
            use is in shell scripts, to iterate over all file systems in a disk 
            image. This tool is installed as part of the 
            <package>libguestfs-tools</package> package.
          </para>
          <para>
            This tool replaces <command>virt-list-filesystems</command> and
            <command>virt-list-partitions</command>.
          </para>
      </listitem>
      </varlistentry>
      <varlistentry>
      <term><command>virt-inspector</command></term>
      <listitem>
          <para>
             A command line tool that can examine a virtual machine or disk image to
             determine the version of its operating system and other information.
             It can also produce XML output, which can be piped into other programs.
             Note that <command>virt-inspector</command> can only inspect one domain
             at a time. This tool is installed as part of the 
             <package>libguestfs-tools</package> package.
         </para>
      </listitem>
      </varlistentry>
      <varlistentry>
      <term><command>virt-ls</command></term>
      <listitem>
         <para>
            A command line tool that lists files and directories inside a virtual
            machine. This tool is installed as part of the 
            <package>libguestfs-tools</package> package.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-make-fs</command></term>
       <listitem>
          <para>
             A command line tool for creating a file system based on a tar archive
             or files in a directory. It is similar to tools like 
             <command>mkisofs</command> and <command>mksquashfs</command>, but it
             can create common file system types such as ext2, ext3 and NTFS, and 
             the size of the file system created can be equal to or greater than the
             size of the files it is based on. This tool is provided as part of the 
             <package>libguestfs-tools</package> package.
          </para>
       </listitem>
      </varlistentry> 
      <varlistentry>
       <term><command>virt-p2v</command></term><!-- confirm with mbooth if it's in Fedora 19.-->
       <listitem>
         <para>
            A graphical tool to convert physical machines into virtual machines.
            This tool is installed as part of the <package>virt-v2v</package> package.
         </para>
       </listitem>
     </varlistentry>
      <varlistentry>
       <term><command>virt-rescue</command></term>
       <listitem>
          <para>
             A command line tool that provides a rescue shell and some simple
             recovery tools for unbootable virtual machines and disk images. It can
             be run on any virtual machine known to <application>libvirt</application>, or directly on disk
             images. This tool is installed as part of the 
             <package>libguestfs-tools</package> package.
          </para>
          <warning>
             <para>
                Using <command>virt-rescue</command> on running virtual machines can
                cause disk corruption in the virtual machine. 
                <command>virt-rescue</command> attempts to prevent its own use on
                running virtual machines, but cannot catch all cases.
             </para>
             <para>
                Using the command with the <option>--ro</option> (read-only) option
                will not cause disk corruption, but may give strange or inconsistent
                results. It is better to avoid using <command>virt-rescue</command>
                on a running virtual machine.
             </para>
          </warning>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-resize</command></term>
       <listitem>
          <para>
             A command line tool to resize virtual machine disks, and resize or 
             delete any partitions on a virtual machine disk. It works by copying the guest image and leaving the original disk image untouched. This tool is installed as part of the 
             <package>libguestfs-tools</package> package.
          </para>
        <important>
             <para>
                Using <command>virt-resize</command> on running virtual machines can
                give inconsistent results. It is best to shut down virtual machines
                before attempting to resize them.
             </para>
          </important>
       </listitem>
      </varlistentry>
      <!--<varlistentry>
       <term><command>virt-tar</command></term>
       <listitem>-->
      <!--This is obsolete upstream, but we haven't shipped the replacement tools
      in RHEL yet.  Probably we will obsolete it in and ship replacements in
      RHEL 6.3.-->
          <!--<para>
            A command line archive tool for downloading and uploading parts of a
            virtual machine's file system. This tool is commonly used for making backups, 
            uploading data, reviewing guest activity, and fixing or customizing 
            guests. This tool is installed as part of the 
            <package>libguestfs-tools</package> package.
          </para>
          <warning>
             <para>
                Using <command>virt-tar</command> with the <option>-u</option> 
                (upload) option on running virtual machines can cause disk corruption
                in the virtual machine. <command>virt-tar</command> attempts to 
                prevent its own use on running virtual machines, but cannot catch 
                all cases.
             </para>
             <para>
                Using <command>virt-tar</command> with the <option>-x</option> 
                (extract) option on running virtual machines will not cause disk 
                corruption, but may give strange or inconsistent results. It is best 
                to shut down virtual machines before attempting to extract files from
                them.
             </para>
          </warning>
       </listitem>
      </varlistentry>-->
      <varlistentry>
       <term><command>virt-top</command></term>
       <listitem>
          <para>
             A command line utility similar to <command>top</command>, which shows
             statistics related to virtualized domains. This tool ships in its own package:
             <package>virt-top</package>.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-v2v</command></term>
       <listitem>
          <para>
            A graphical tool to convert virtual machines from Xen and VMware hypervisors
            to run on KVM. This tool ships in its own package: 
            <package>virt-v2v</package>.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-viewer</command></term>
       <listitem>
          <para>
            A minimal tool for displaying the graphical console of a virtual machine via
            the VNC and SPICE protocols. This tool ships in its own package: 
            <package>virt-viewer</package>.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-what</command></term>
       <listitem>
          <para>
            A shell script that detects whether a program is running in a virtual machine.
            This tool ships in its own package: <package>virt-what</package>.
          </para>
       </listitem>
      </varlistentry>
      <varlistentry>
        <term><command>virt-who</command></term>
        <listitem>
          <para>
            The <package>virt-who</package> package is a Fedora host agent that queries <application>libvirt</application> for guest UUIDs. It then passes that data to the local entitlement server for the purposes of issuing certificates. This tool ships in its own package: <package>virt-who</package>.
          </para>
        </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-win-reg</command></term>
       <listitem>
          <para>
            A command line tool to export and merge Windows Registry entries from a
            Windows guest, and perform simple Registry operations. This tool is installed 
            as part of the <package>libguestfs-tools</package> package.
          </para>
          <warning>
             <para>
                Using <command>virt-win-reg</command> on running virtual machines will
                cause irreversible disk corruption in the virtual machine.
                <command>virt-win-reg</command> attempts to prevent its own use on 
                running virtual machines, but cannot catch all cases.
             </para>
          </warning>
          <warning>
             <para><!-- REWORD!-->
                Modifying the Windows Registry is an inherently risky operation, as the
                format is deliberately obscure and undocumented. Changes to the registry 
                can leave the system unbootable, so ensure you have a reliable backup
                before you use the <option>--merge</option> option.
             </para>
          </warning>
       </listitem>
      </varlistentry>
      <varlistentry>
       <term><command>virt-xml-validate</command></term>
       <listitem>
          <para>
            A command line tool to validate <application>libvirt</application> XML files for compliance with the
            published schema. This tool is installed as part of the
            <package>libvirt-client</package> package.
          </para>
       </listitem>
      </varlistentry>
   </variablelist>
</section>
</chapter>