VMWare和Hyper-V的比较.doc

微软Hyper-V R2与VMware vSphere的功能性对比【WatchStor独家译文】在虚拟化大战中，微软有些姗姗来迟，但是却在虚拟化领域成为VMware的主要竞争对手。最近几个月，两家厂商都发布了他们各自hypervisor产品微软Hyper-V和VMware的vSphere的重要升级。本文我们对比两家厂商的hypervisor产品的常用功能特性，不过我们并不会特别推荐那一款产品最适合你的企业机构。下面这个表格对比了vSphere的四个版本以及Hyper-V R2的三个版本。表格下面，我将解释每一个对比项。（产品备注：发布vSphere的时候，VMware已经公布了他们hypervisor产品的Enterprise Plus 。Enterprise Plus版本提供了之前产品版本没有的更多功能。用户必须从Enterprise版本升级到Enterprise Plus版本才能享受到这些功能）最多主机处理器。这一项表明了系统可识别的物理主机处理器数量。记住一点，Windows卷是限于Windows操作系统的，而并不限制Hyper-V。最多内核/处理器。这一项表明了系统可识别每个物理处理器上有多少个处理内核。最多虚拟SMP。在一个独立虚拟机中，这代表支持虚拟处理器的最多数量。注释：这是最大值；并不是每个客户操作系统可以支持的最多虚拟处理器数量。最多主机RAM（GB）。hypervisor可识别的最高RAM容量。最多RAM/虚拟机。一个虚拟机上可分配的最高RAM容量。故障转移节点。可以集群到一起的最多物理主机数量。N/A代表某些hypervisor版本不支持故障转移集群。内存环境。hypervisor支持内存过量分配吗？内存过量分配是vSphere中提供的一项技术，允许管理员向虚拟机中分配比主机中更多的RAM容量。有不少关于这个话题的支持或者反对的文章，但是很显然，分配超出物理需求的更多资源将增加虚拟机整体密度。在生产环境中使用内存过量分配适合于每个机构。也就是说，在我看来，当在合适的环境下使用，这个技术可以带来重要的好处。透明页面共享。透明页面共享是实现内存过量分配的一种方法。使用这种技术，虚拟机之间共享的常用代码本身就是被虚拟化了的。举个例子，你的VDI环境中有100个运行Windows XP的虚拟机。使用透明页面共享，RAM并不一定是服务器桌面密度的一个主要限制因素。VMware在这项技术方面比较突出。实时迁移/VMtion。它是hypervisor在主机服务器之间迁移虚拟机而不需要宕机时间的一项技术，也被认为是虚拟化解决方案带来最重要可用性好处之一。同步实时迁移。一款产品是否可以利用它的实时迁移功能同步地在多个节点之间迁移多个虚拟机？每个主机的实时客户。在一台负荷最大主机上可以支持的虚拟机数量。在现实环境中，我很惊讶地发现很多人正在接近这个极限。虚拟化是一个削减成本的好方法，但是也是有局限性的。实时客户/HA集群节点。如果你正在一个集群中运行hypervisor的话，这就是指集群中任何一个主机上可以激活的最多虚拟机数量。对于经过update 1的vSphere，如果你有8个或者少于8个集群主机的话，你在每个主机上可以运行多达160个虚拟机。如果是9个或者更多集群主机，虚拟机数量会锐减到40。分布数资源调度（DRA）。DRA是一项能够根据业务规则在主机之间迁移虚拟机的技术，这对那样对SLA要求很严格的企业机构来说有很大的帮助作用。每个虚拟机的快照。对一个虚拟机可保留的最多快照数量。一个快照就是一个虚拟机的时间点镜像，它可作为备份和恢复机制的一部分。我发现快照是非常有用的，尤其是变化很大的工作站方面。自动精简配置。在任何服务生命周期之初应该作出的一个决策就是，应该给这个系统分配多少存储空间？分配太多，就会浪费宝贵的磁盘空间，太少的话，服务就会中断。为了维持稳定的服务，大多数IT机构会通过过量配置存储来确保存储容量不会耗尽，但是长此以往通信量越来越大。想象一下，如果你有100个虚拟机，每个虚拟机都有45GB未使用的空间。有了自动精简配置技术，你可以取得一个最佳平衡点。你可以配置重组的磁盘空间来满足需求，但是实际上，hypervisor根本就没有分配。随着空间逐渐被占满，hypervisor将提供更多空间来满足最大卷容量。尽管自动精简配置技术不应该被用于大规模工作负载，但是它对于那些希望不中断通信的企业机构来说有很大帮助。存储实时迁移。这种功能实现了存储阵列之间虚拟机磁盘文件的实时迁移，向虚拟环境中增加了更高的可用性。分布式交换机。VMware和微软都推出了虚拟交换机产品，但是只有VMware更近了一步，推出vSphere Enterprise Plus版本的分布式交换机（Distributed Switch）。据VMware称：“分布式交换机在虚拟机在多主机之间迁移的过程中维持了网络的正常运转，而且可以进行在线监控和提供集中的防火墙服务。当虚拟机从一个物理服务器迁移到另一个物理服务器的时候，它提供了一个监控和维持虚拟机安全性的架构，能够使用第三方虚拟交换机（例如Cisco Nexus 1000V）来扩展类似的物理网络功能和控制虚拟网络。”简而言之，这项新功能能提高了VMware的可用性和安全性。直接I/O。这是虚拟机避过hypervisor层、直接访问物理I/O硬件设备的一项功能。vSphere中对这种功能的支持是有限制的，该产品支持对少数存储和网络控制器的直接I/O操作。这项名为VMDirectPath I/O的功能可以提供整体性能，因为它消除了通过hypervisor访问硬件时可能发生的“虚拟化处罚”。VMDirectPath也有一些缺点，例如硬件需求的原因使得VMotion不起作用了。（注释：这项功能与Hyper-V支持的直接访问磁盘功能是不同的）最大分区（TB）。什么是hypervisor支持的最大分区？基于VHD的卷（例如Hyper-V R2中所采用的）最大可以达到2TB，但是如果你避过VHD选项，直接使用磁盘呢？应用防火墙（vShield）。据VMware称，“VMware vShield Zones能够帮助你监控、记录和阻挡ESX主机或者集群主机之间进入虚拟机的传输，而无需通过静态物理阻塞点转向传输。你可以根据由逻辑组织和可信边界定义的多区域之间桥接防火墙或者独立虚拟机。允许或者被阻隔的活动都将被记录下来，详细地以图表或者分析形式呈现。”换句话说，你不需要通过外部切换一个路由器运行传输防止来自外部的应用。虚拟实例权限。这是微软特有的一种权限，可以大幅度降低Windows环境中Hyper-V R2的整体成本。如果你使用数据中心版本的Windows操作系统，那么你想要运行多少个基于Windows Server的虚拟机都可以，同时不会发生更多额外服务器许可成本。hypervisor许可。产品许可的一种方式，基于每个主机或者每个处理器。我所在的大学一直运行VMware的虚拟化服务，为什么？主要因为是经过我们验证的。也就是说，预算压力迫使我们不时地重新评估服务和优先级。VMware产品的起步总成本较高是一个问题。随着微软不断完善Hyper-V R2，我们将关注它的进展来决定是否或者什么时候可以用它来取代VMware尽管对VMware VDI的投资可能会让我们长期锁定VMware。我喜欢VMware的内存过量配置功能，相信如果使用得当的话，它将成为密度方面的一个重要因素，尤其是在我们考查虚拟化桌面计算机的时候。另一方面，对于每个主要采用微软产品的企业机构来说，Hyper-V R2让微软的hypervisor产品极具竞争力。【WatchStor独家译稿，未经许可禁止转载。合作伙伴请注明原作者及出处为WatchS】VMware/EMCMicrosoftURLV/windowsserver2008/en/us/hyperv-main.aspxITComparison CommentsVMware site is a bit easier to browse in regards of virtualization than Microsoft site due to the fact its their core business, in compare with Microsoft with tons of products.Product NameVMware vSphere 4Microsoft Windows Server 2008 R2 Hyper-VITComparison CommentsPlease note these are the full fledge versions of both VMware ESX & Hyper-V. As mentioned in the introduction above we will not cover the slimmer version of both products. That will be left to another comparison.Pricing range Management CostVMware vSphere Standard $795 per CPUVMware vSphere Advanced $2245 per CPUVMware vSphere Enterprise $2875 per CPUVMware vSphere Enterprise Plus $3495 per CPUVirtual vCenter server $4995 to manage the full infrastructureWindows Server 2008 R2Standard $1,209 per HostWindows Server 2008 R2Enterprise $3,999 per HostWindows Server 2008 R2Datacenter $2,999 per HostSystem Center Server Management Suite Datacenter (SMSD) $1,498 per processorITComparison Comments -: MS Windows Hyper-V 2005 R2 VS VMware VI3:-We had a large debate internally on how to post the prices of both products & on which base to compare them. We have almost got to the point we were about to exclude pricing from the comparison. Though at the end we decided to include the Windows 2008 pricing in our equation, as there is no way you can run MS Windows 2008 R2 Hyper-V without paying for Windows 2008 R2 License. Dont jump at us yet, but we are not covering ESXi neither Hyper-V 2008 R2 Server in this comparison, where both of them are a free product so the word free was left out of both products in this comparison. We believe that shall be fair enoughPlease dont get mislead by the word Hyper-V is free, as its not always that way. If you are going to use MS Windows 2008 R2 Hyper-V, you will always have to pay for the Windows 2008 R2 OS even if you are are planning to only run Linux or Windows 2003 where you are not going to use that license for anything else.- Another important side of the cost of Hyper-V Virtualization Solution & VMware virtualization which usually get ignored is the management application cost. VMware has Virtual Center for one fixed cost of Virtual center for $4995 and can manage unlimited hosts, where with MS to get the same functionality you will need to get System Center Management Suite Enterprise which cost $1498 per CPU. So the management hidden cost for Hyper-V will depend on how many servers your virtualization infrastructure will have. It can go quite steep hidden cost with hyper-V.- When it coming to cost, you should compare the versions which give you the features you need of both products. If you require all the Hyper-V features, then your equivalent to that will be VMware ESX advanced, as the feature in the VMware Enterprise & Enterprise Plus is still not available at any version in Hyper-v. Furthermore, the advanced version has some features that is not available in Hyper-v, but its the least version that has the full equivalent features to Hyper-V.In addition, in VMware vSphere you can run more virtual machines on the same specs machine as VMware offer memory over commitment and waste less resource than Microsoft Hyper-V solution in most cases. Dont let the initial cost per host fool you. Make sure you calculate your cost per VM or preferably by service, not per initial cost of each host. Remember your business require services not virtualization hosts & will check the cost per the service provided, not per Virtualization Host. It does not matter for them if you have obtained the Virtualization host for a cheaper price, but end up costing them more per service. For example, if your first virtualization solution host cost you $8,000 where the second solution cost you $10,000 per host where the first solution require 10 hosts to run the solution & the second solution require only 7 hosts to run the solution. You will find the second solution to be more cost effective although its more expensive per host.- If you are getting one thing of the cost comparison then let it be to do a TCO per service study of the solution you are going for instead of just the initial cost of your Virtualization hosts. Make sure you calculate the management tools & maintenance of the solutions you are deciding on as these are going to be your real cost. Another great thing is to always ask for a proof of concept for the different solutions, as that usually will make calculating your ROI & TCO more realistic.Primary usageProduction Environmentsneaking into production, but for most companies still at testing & developmentenvironment. ITComparison CommentsAfter the release of MS Windows server HyperV R2, HyperV started sneaking into the production of enterprise companies. Its not nearly as spread as VMware into the enterprise production environment, but it started to show up.In the other side VMware have captured the major share of the virtualization solutions used in production environment for a while.Host SpecificationsSupported CPUs 64-bit Intel/AMD64-bit Intel-VT/AMD-V capable CPUITComparison CommentsHyper-V R2 require an Intel-VT/AMD-V capable CPU, where VMware ESX 4.0 does not require it unless you need to run 64-bit VMs on it. That allow you to run VMware ESX 4 over a relatively older servers than possible with Hyper-V. An example of these servers would be IBM X346, which support 64-bit but does not have Intel-VT. X346 is capable of running VMware ESX 4, but not Hyper-V. Its worth noticing in case you are planning to re-use servers of that generation in your virtualization environment.Logical Processors/host 6464Memory Supported 1TB1TBMax allowed Failover Nodes 3216Running guest/host 320384Running guest/ cluster node 160 64I/O Devices SupportedIDE, SCSI, SAS, SATA, FC, 1Gband 10Gb Ethernet, iSCSI, NFS,FCOE, InfinibandIDE, SCSI, SAS, SATA, FC, 1Gb and 10Gb Ethernet, iSCSI, CIFS, FCOE, InfinibandMemory over-commitment YesNoTransparent Page Sharing YesNoITComparison CommentsMost of the host specifications numbers above are very close, & you might not even need to reach most of these limits. Though it is important to note the memory over-commitment & Transparent Page Sharing in VMware is claimed to allow you to run VMs with up to twice the amount of the memory in your system. In most environments 1.6 memory over-commitment ratio is quite achievable. Memory over-commitment & Transparent Page Sharing can cut the number of required hosts to run your environment.Supported HardwareRefer to VMware supported Hardware list. Most hardware that supported by Windows 2008 is supported by Hyper-V.Used DriversSpecialized Virtualization DriversGeneral Windows 2008 DriversStorage Multi-pathingSupported Out of the boxDepend on the HBA & storage vendor.Network card teamingSupported out of the box.Depend on the Network Card VendorITComparison CommentsWhen it come to supported hardware & used drivers, VMware & Microsoft has followed a totally different path. There is a tradeoff for each approach. While Microsoft Hyper-V R2 support more hardware as it support every piece of Hardware that MS Windows 2008 R2 support, there is a large trade off for that they use a general operating system drivers. The problem with the general operating system drivers its totally dependant on the hardware vendor & at many cases can tear windows unstable. Its well-known that the major some of windows crashes are due to a bad hardware driver. In addition, a generic operating system driver is not always optimized to run a virtualization load.As MS Hyper-V R2 is totally dependant on the hardware vendor in providing their drivers, the availability of NIC Teaming & multipathing support is highly dependant on your hardware vendor.VMware has used a different approach, where they have integrated a virtualization optimized drivers into their out of the box installation. This approach guarantee the performance & stability of the drivers, as well ensure NIC Teaming & Multipathing is available out of the box with any VMware installation without depending on what the hardware vendor provide. The trade-off to VMware approach is they get to support a bit less hardware. Though its worth noticing that VMware supported hardware matrix has grown to include most of the well-known hardware vendor to the limit it does not really limit your hardware choices any more.Virtual Machine SpecificationsMax Virtual SMP84Max Memory/VM255GB64GBDirect I/OVMDirectPath I/ONot AvailableSnapshot/VM3250Thin ProvisioningYesYesSupported storage of guest VMsDirect, SAN, NAS, iSCSIDirect, SAN, iSCSISupported Guest OSMicrosoft Supported Server Operating Systems- MS Windows 2008 R2 (Up to 8 vCPU) (Standard/Enterprise/Datacenter/Web/ Small Business) - MS Windows 2008 x86/x64 (up to 8 vCPU) (Standard/Enterprise/Datacenter/Web/ Small Business) - MS Windows 2003 R2 (x86/x64) (Up to 8 vCPU) (all service packs) - MS Windows 2003 (x86/x64) (Up to 8 vCPU) (all service packs) - MS Windows 2000 x86 (up to 8 vCPU) (SP3/SP4) - Windows NT 4.0 Service Pack 6a Server- MS Windows 2008 R2 (Up to 4 vCPU) (Standard/Enterprise/Datacenter) - MS Windows 2008 x86/x64 (up to 4 vCPU)(Standard/Enterprise/Datacenter) - MS Windows 2003 R2 (x86/x64) (Up to 2 vCPU) (minimum SP2) - MS Windows 2003 (x86/x64) (Up to 2 vCPU) (minimum SP2) - MS Windows 2000 x86 (up to 1 vCPU) (minimum SP4)(Microsoft Supported Client Operating Systems)- MS Windows 7 x86/x64 (up to 8 vCPU) (All editions are supported) - Windows Vista x86/x64 (up to 8 vCPU) (minimum of SP1)- Windows XP Professional x86/64 (with or without SP1/SP2/SP3) (up to 8 vCPU)- Windows 2000 Professional- Windows 3.1/95/98 - Windows NT 4.0 Service Pack 6a Workstation.- MS Windows 7 x86/x64 (up to 4 vCPU) (Professional & above)- Windows Vista x86/x64 (up to 2 vCPU) (minimum of SP1) - Windows XP Professional x86 SP3 (up to 2vCPU)- Windows XP Professional x86 SP2 (up to 1vCPU)- Windows XP Professional x64 SP2 (up to 2 vCPU)Non-Microsoft Supported Operating SystemsVMware support a massive list of Linux/Unix & Non Microsoft Operating Systems. the below is just a wide selection of them for the full list you will need to visit: VMware OS Compatibility Guide - Redhat Enterprise Linux 2.1/3/4/5 x32/x64 (up to 8 vCPU)- Redhat Linux 7/8/9 (up to 8 vCPU)- Suse Linux (most versions are supported including 7/8/9/10/11 & Open Suse)- Ubuntu (many version are supported)- Solaris 10/ Netware/ FreeBSD/CentOS/ & other Linux OSs.- SUSE Linux Enterprise Server 10 x86/x64 SP1 (up to 1 vCPU) - SUSE Linux Enterprise Server 10 x86/x64 SP2 (up to 1 vCPU)- SUSE Linux Enterprise Server 11 x86/x64 (up to 1 vCPU)- Red Hat Enterprise Linux (RHEL) 5.2, 5.3, 5.4 x86/x64 (up to 1 vCPU)ITComparison CommentsIts obvious that VMware has the lead on the number of supported operating systems on its Virtualization platform. Even when looking at Microsoft own OS, you are limited by the number of supported CPUs & older operating systems are not supported at all. Even Windows 2008 is limited to 4 vCPU, Windows 2003 for 2 vCPU, & Windows 2000 for 1 vCPU. Even with the very limited of non Microsoft operating systems hyper-V R2 support, It impose a killing limitation of only 1 vCPU supported for any Non-Microsoft OS. The limit on the number of vCPUs & amount of memory allowed to VMs can degrade the performance & put boundaries in front of virtualizing larger workloads on Hyper-V. Vmware has the lead on supported a higher specs VMs, which gives it advantage at handling larger workload.FeaturesManagement toolsVMware vCenter 4.0System Center Server Management SuitesITComparison CommentsIf you have wondered why System Center Server Management Suite is used at this comparison & not Microsoft System Center Virtual Machine Manager 2008 R2, then we must mention that MS SCVMM alone does not offer much comparing to vCenter. MS SCVMM get most of its value by integrating with: - System Center Operations Manager 2007 R2 - System Center Configuraiton Manager 2007 R2- System Center Data Protection Manager 2007Although after integrating SCVMM with SCOM, SCCM, SCDPM it get a nice set of functionality setting them up & getting them functioning is quite more intense than vCenter. Its worth mentioning the extra amount of resources required to install them hardware wise & Administration wise. It definitely has took us a considerably longer & more hardware to setup System Center Server Management Suites that vCenter.Live MigrationYesYesSimultaneous Live MigrationYesNoITComparison CommentsOne of the major improvement of Hyper-V R2 over Hyper-V V1 is the inclusion of Live Migration, though its limited to one virtual machine migration at a time. The lag of Simultaneous Live migration in Hyper-v R2 can be a major slow down in case you need to evacuate the host as fast as possible, as you will have to wait for each machine to finish the migration to start the next VM migration. Its worth noticing that VMware support Simultaneous migration. While evaluating Hyper-V R2 live migration continuously in the same fashion we have stressed VMware VMotion, we have found out VMware VMotion to prove being more mature & stable. We have faced few kernel panic on Redhat 4 & 5 VMs & Blue Screen on Windows 2003 SP2 that we were running on Hyper-V while migrating them across hosts continuously. Its worth mentioning these failures were not consistent & the migration often worked where it failed about 5% of the time for these particular operating systems.Storage Live MigrationYesNoITComparison CommentsStorage live migration is still a feature that Hyper-V does not offer & lag behind VMware on it. VMware has offered Storage VMotion since VMware VI3. Our team was actually surprised that Microsoft did not offer it in Hyper-V R2, as most of MS Hyper-V customers would be moving from a single VM per store to Multiple VM per store design with Hyper-V R2 where storage live migration would have been very handy. Microsoft Hyper-V R2 customers who decided to move to multi-VM per store design will have to go through downtime for every VM they want to move to the new dat