Kernel SamePage Merging (KSM) allows identical memory pages to be merged by the kernel into a single page shared between one or more processes. This feature is leveraged by KVM to allow multiple, similar, guest virtual machines to have a reduced memory footprint. Because memory is shared, the combined memory usage of the guests is reduced.

For further details refer to http://fedoraproject.org/wiki/Features/KSM and http://lwn.net/Articles/306704/

Enable KVM guests to use huge page backed memory in order to reduce memory consumption and improve performance by reducing CPU cache pressure. Users of KVM guests using huge page backed memory should experience improved performance with some savings in host memory consumption. The performance benefit is workload dependent.Using huge pages for guest memory does have a downside, however - you can no longer swap nor balloon guest memory.

For further details refer to: http://fedoraproject.org/wiki/Features/KVM_Huge_Page_Backed_Memory.

Network interfaces may now be added to a running KVM guest using libvirt/virt-manager without the need to restart the guest.

For further details refer to: http://fedoraproject.org/wiki/Features/KVM_NIC_Hotplug.

The native disk image file format of qemu is qcow2. Qcow2 provides enhanced features over raw images, including: base images, snapshots, compression, and encryption.

Users wishing to protect guest machine data from host crashes commonly disable write caching on the host. Previously, this led to very poor performance for guests in qcow2 images.

The I/O performance of qcow2 disk images has been greatly improved. Users who did not use qcow2 because of the poor performance may consider to switch and take advantage of the additional features the format provides over raw disk images.

For further details refer to: http://fedoraproject.org/wiki/Features/KVM_qcow2_Performance and http://www.gnome.org/~markmc/qcow-image-format.html.

KVM guests are presented with an emulated hardware platform or application binary interface that includes (e.g. a CPU model, APIC, PIT, ACPI tables, IDE/USB/VGA controllers, NICs etc.). When QEMU is updated to a new version, some aspects of this platform may change as new hardware capabilities are added. This is problematic for Windows guests where a guest ABI change may require a installation to be reactivated.

Guest virtual machines will now be presented with the same ABI across QEMU upgrades.

For further details refer to: http://fedoraproject.org/wiki/Features/KVM_Stable_Guest_ABI and http://fedoraproject.org/wiki/KVM_Stable_Guest_ABI_Design_Notes.

Added very late in the Fedora 11 development cycle, libguestfs is now an official feature in Fedora 12. libguestfs is a library for accessing and modifying guest disk images. Using Linux kernel and qemu code, libguestfs can access any type of guest filesystem that Linux and QEMU can.

The following tools are provided or augmented by libguestfs:

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ:

Commonly used host network configurations, like bridges, bonds, VLAN's and sensible combinations thereof may now be created using the general-purpose network configuration library, netcf. Enhancements to the libvirt API expose this new functionality to remote managment hosts with libvirtd

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ:

Single Root I/O Virtualization is a PCI feature which allows virtual functions (VF) to be created that share the resources of a physical function (PF). The VF devices are assigned to guest virtual machines and appear as physical PCI devices inside the guest. Because the guest OS is effectively driving the hardware directly, the I/O performance is on par with bare metal performance.

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ:

QEMU guests now make use of the more modern and currently maintained gpxe rather than the deprecated etherboot tool for PXE booting.

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ:

Changes have been introduced for QEMU/KVM virtual machines to improve host security in the event of a flaw in the QEMU binary.

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ:

Fibre Channel N_Port ID Virtualization or NPIV allows the creation of multiple virtual N_Ports on a single physical host bus adapter. The libvirt node device APIs have been extended to create and destroy virtual adapters using NPIV.

The APIs permitting storage discovery and pool creation have been extended to discover and rescan storage on a per-SCSI-host basis. Administrators may now discover, configure, and provision storage for virtual machines without the need for multiple tools.

ਹੋਰ ਜਾਣਕਾਰੀ ਲਈ ਇਹ ਵੇਖੋ: