VMware vSphere 5 vMotion:性能提升与最佳实践

3星 · 超过75%的资源需积分: 10 153 浏览量更新于2024-07-30 收藏 2.41MB PDF 举报

"VMware vSphere vMotion 是一种关键技术，允许在不同的vSphere 5主机之间实时迁移虚拟机，对最终用户几乎没有可感知的影响。vMotion是多项VMware技术的基础，如vSphere分布式资源调度器(DRS)和vSphere分布式电源管理(DPM)。它为管理员提供了巨大的好处，例如避免服务器停机、便于故障排查和提高灵活性。在vSphere 5中，vMotion引入了多项性能改进，使得即使是运行重型企业级应用的大型虚拟机也能轻松实现迁移，且开销极小。这份白皮书简要介绍了vMotion技术，vSphere 5中的性能增强，以及该技术对各种一级应用程序工作负载的性能影响。同时，它还提供了量化vSphere 5与vSphere 4.1之间性能差异的数据，并提出了使用vMotion时应遵循的最佳实践。 vMotion的架构包括虚拟设备状态、网络和SCSI设备连接、虚拟机的物理内存等关键组件。迁移过程分为三个阶段：客人跟踪阶段、预拷贝阶段和切换阶段。在vSphere 5中，有多个网络适配器用于vMotion，实现了Metro vMotion功能，以及Stun During Page Send (SDPS)等优化。此外，还有其他性能优化措施，提升了vMotion在处理复杂工作负载时的性能。性能测试配置和方法论包括了测试环境的设定、vMotion性能的衡量方式、捕捉时间细节等。在web环境和邮件/消息环境中进行了测试，使用了负载生成软件来模拟真实工作负载。测试结果显示，无论是在网页服务还是邮件服务的场景下，vMotion都能保持高效稳定，任务异常数量极少，表明其在各种业务场景下的出色性能。 vSphere 5的vMotion技术通过不断的性能优化，为数据中心提供了更强大的灵活性和可靠性，确保了在迁移过程中对业务连续性的影响最小，从而提高了IT基础设施的效率和可用性。遵循最佳实践可以进一步提升vMotion的使用体验和性能表现。"

TECHNICAL WHITE PAPER / 5

VMware vSphere vMotion Architecture, Performance

and Best Practices in VMware vSphere 5

Physical Memory of a Virtual Machine

The physical memory of the virtual machine is by far the largest component that needs to be transferred during

a migration. The virtual machine’s physical memory can be as large as 1TB on vSphere 5, so the eciency with

which the memory is transferred plays a critical role in vMotion performance.

To allow a virtual machine to continue to run during the process of memory transfer and to achieve the desired

amount of transparency, the memory state of the virtual machine is transferred in multiple phases. The following

describes each phase along with how a guest workload might be impacted in each phase.

Phase 1: Guest Trace Phase

The guest is staged for migration during this phase. Traces are placed on the guest memory pages to track any

modiﬁcations by the guest during the migration. Tracing all of the memory can cause a brief, noticeable drop in

workload throughput. The impact is generally proportional to the overall size of guest memory.

Phase 2: Precopy Phase

Because the virtual machine continues to run and actively modify its memory state on the source host during

this phase, the memory contents of the virtual machine are copied from the source vSphere host to the

destination vSphere host in an iterative process. The ﬁrst iteration copies all of the memory. Subsequent

iterations copy only the memory pages that were modiﬁed during the previous iteration. The number of precopy

iterations and the number of memory pages copied during each iteration depend on how actively the memory is

changed on the source vSphere host, due to the guest’s ongoing operations. The bulk of vMotion network

transfer is done during this phase—without taking any signiﬁcant number of CPU cycles directly from the guest.

One would still observe an impact on guest performance, because the write trace ﬁres during the precopy phase

will cause a slight slowdown in page writes.

Phase 3: Switchover Phase

During this ﬁnal phase, the virtual machine is momentarily quiesced on the source vSphere host, the last set of

memory changes are copied to the target vSphere host, and the virtual machine is resumed on the target

vSphere host. The guest brieﬂy pauses processing during this step. Although the duration of this phase is

generally less than a second, it is the most likely phase where the largest impact on guest performance (an

abrupt, temporary increase of latency) is observed. The impact depends on a variety of factors not limited to but

including network infrastructure, shared storage conﬁguration, host hardware, vSphere version, and dynamic

guest workload.

TECHNICAL WHITE PAPER / 6

VMware vSphere vMotion Architecture, Performance

and Best Practices in VMware vSphere 5

Enhancements in vSphere 5

Using Multiple Network Adaptors for vMotion

vSphere 5 adds a multi–network adaptor feature that enables the user to utilize multiple network adaptors for

vMotion. Test results, discussed later, show that migration times can be dramatically reduced when using this

feature. The VMkernel will transparently load balance vMotion trac over all of the vMotion-enabled vmknics to

saturate all of the connections. In fact, even where there is a single vMotion, VMkernel uses all of the available

network adaptors to spread the vMotion trac.

Metro vMotion

vSphere 5 introduces a new latency-aware Metro vMotion feature that not only provides better performance over

long latency networks but also increases the round-trip latency limit for vMotion networks from 5 milliseconds to 10

milliseconds. Previously, vMotion was supported only on networks with round-trip latencies of up to 5 milliseconds.

Stun During Page Send (SDPS)

vSphere 5 introduces a new enhancement that ensures vMotion will not fail due to memory copy convergence

issues. As noted in the “Architecture” section, transfer of the virtual machine’s memory contents during the

vMotion process involves an iterative precopy procedure. In most cases, a precopy iteration should take less

time to complete than the previous iteration. However, a pathological case where the virtual machine modiﬁes

memory faster than it can be transferred—due to workload characteristics or network infrastructure

limitations—results in aborting vMotion in vSphere 4.1 and prior releases, because precopy fails to make forward

progress. The enhancement in vSphere 5 slows down the virtual machine during such pathological cases and

ensures that the memory modiﬁcation rate is slower than the precopy transfer rate, thereby preventing any

possible vMotion failures.

Other Performance Optimizations in vSphere 5

Other performance optimizations in vSphere 5 include the following:

•Signicantimprovementstominimizetheimpactofmemorytracing

•Numerousimprovementstoreducetheamountoftimeneededfortheguesttoresumeanormallevelof

performance after vMotion

•NewoptimizationstoenablevMotiontoeectivelysaturatethe10GbEbandwidthduringthemigration

剩余25页未读，继续阅读

spell007

粉丝: 404
资源: 10

VMware vSphere 5 vMotion:性能提升与最佳实践

VMware-VMvisor-Installer-6.5.0-4564106.x86_64.iso镜像文件

CCIE-DC vSphere6.0专题视频.zip

PA-VM-ESX-7.1.0.zip

vmware-vmvisor-installer-6.7.0-8169922.x86_64.iso

vmware-vmvisor-installer-7.0u2a-17867351.x86_64.iso

vmware-vcsa-all-7.0.0.iso

在VMware vSphere 6.x平台上，如何规划物理和虚拟资源的层次结构以实现高性能和高可用性？

vsphere clinet迁移虚拟服务器时出现这个报错，"目标" 主机“192.168.0.20”上的 vMotion 接口未配置 (或者配置错误)。 怎么处理？

在VMware环境中的思科FEX应如何配置以启用VM-FEX模式，从而优化虚拟机网络性能？

如何配置vMotion网络？

最新资源

vsphere clinet迁移虚拟服务器时出现这个报错，"目标" 主机“192.168.0.20”上的 vMotion 接口未配置 (或者配置错误)。怎么处理？