RHEL 6.5 中的KVM虛擬化新特性

昨天看到redhat官網的資料，RHEL 6.5 中會增長許多KVM虛擬化新特性，有些特性在實際工做中可能很是有前景，好比windows虛擬機的agent，原生的支持glusetFS。

抑制不了本身的興奮，我花了半天時間翻譯了這一部分，和你們共享。

如下部分引用自以下鏈接：

https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6-Beta/html-single/6.5_Release_Notes/index.html

5.1. KVM

Improved Support For the VMDK Image File Format 改進對VMDK文件鏡像的支持

Red Hat Enterprise Linux 6.5 includes a number of improvements to read-only support for Virtual Machine Disk, or VMDK, p_w_picpath file formats, including its subformats, as created by many VMware products.

RHEL 6.5 增長了多種只讀方式的虛擬機磁盤鏡像格式的支持，VMDK等，包括VMWare產品的子格式。

Windows Guest Agent Fully Supported Windows客戶端Agent的全面支持

The Windows guest agent is now fully supported and delivered with its own installer in the Supplementary channel together with virtio-win drivers.

如今全面支持Windows客戶端Agent，而且和virtio-win的驅動一塊兒在支持渠道發佈和交付。

Support for the VHDX Image File Format 支持VHDX文件鏡像格式

Red Hat Enterprise Linux 6.5 includes read-only support for Hyper-V virtual hard disk, or VHDX, p_w_picpath formats, as created by Microsoft Hyper-V.

RHEL 6.5 以只讀的方式支持Hyper-V的 虛擬化硬盤，VHDX鏡像格式，爲微軟的虛擬化引擎Hyper-V建立。

Native Support for GlusterFS in QEMU QEMU 原生的支持GlusterFS

Native Support for GlusterFS in QEMU allows native access to GlusterFS volumes using the libgfapi library instead of through a locally mounted FUSE file system. This native approach offers considerable performance improvements.

QEMU 使用libgdapi原生的支持GlusterFS，取代經過linux FUSE方式掛載，原生方式的支持大大提升了性能。

Support for External Backup of Live Virtual Machines 支持外部的備份工具在線備份虛擬機

Third-party applications running on the host are now able to access the guest p_w_picpath contents in read-only form, thus being able to copy files and perform backups.

第三方應用如今能夠經過只讀方式讀取虛擬機的鏡像目錄，這樣就能夠拷貝文件和執行備份。

CPU Hot Plugging for Linux Guests Linux虛擬機CPU熱添加

CPU hot plugging and hot unplugging are supported with the help of the QEMU guest agent on Linux guests; CPUs can be enabled or disabled while the guest is running, thus mimicking the hot plug or hot unplug feature.

QEMU支持Linux 虛擬機的CPU熱添加，虛擬機運行的時候能夠禁止或者啓用CPU，這樣能夠模擬CPU的熱添加。

Application-Aware freeze and thaw on Microsoft Windows with VSS Support on qemu-ga-win Windows 系統上經過qemu-ga實現應用的凍結和喚醒

VSS (Volume Shadow Copy Service) is a Microsoft Windows API that allows, among other things, the notification of applications for proper, consistent freeze and thaw operations. With this feature, snapshots taken while the virtual machine is running are consistent through the whole stack (from the block layer to the guest applications) and can be used for backup purposes. For more information, see the Virtualization Administration Guide

微軟的卷 影 復 制 服 務 支 持 Windows API，另一面，能夠確切通知應用，保持應用凍結和喚醒時候的一致性，有了這個特性，在虛擬機運行的時候能夠經過整個棧（從塊設備層到虛擬機應用層）建立一致性的快照以達到備份的目的，瞭解更多的信息，請參閱文檔《Virtualization Administration Guide》

Application-Aware freeze and thaw on Linux Using qemu-ga Hooks Linux系統上經過qemu-ga鉤子實現應用的凍結和喚醒

Similar to the Windows VSS version, application-consistent snapshots can be created with the use of scripts that attach to the QEMU guest agent running on the guest. These scripts can notify applications which would flush their data to the disk during a freeze or thaw operation, thus allowing consistent snapshots to be taken.

同Windows VSS的版本類似，在虛擬機上使用QEMU agent 腳本能夠建立應用一致的快照。這些腳本能夠通知應用在應用被凍結或者喚醒操做的時候它應該刷數據到硬盤上，這樣就可產生應用一致的快照。

Conversion of VMware OVF and Citrix Xen Guests to KVM Guests 支持VMWare OVF和xen的虛擬機轉化成KVM的虛擬機

The virt-v2v conversion tool has been upgraded to an upstream version to support conversion of VMware Open Virtualization Format (OVF) and Citrix Xen guest conversion to KVM.

新升級的virt-v2v的工具支持將VMware的開放虛擬化格式(OVF)和思傑的虛擬機轉換成KVM虛擬機。

Increased KVM Memory Scalability 虛擬機更多的內存支持

KVM virtual memory scalability in a single guest has been increased to 4TB.

KVM虛擬機內存擴展支持到4TB。

Support of Volume Control from within Microsoft Windows Guests 支持windows虛擬機內部的音量控制

Users can now fully control the volume level on Microsoft Windows XP guests using the AC'97 codec.

使用windows xp 虛擬機的用戶如今能夠徹底控制AC`97的音量。