We’re pleased to announce the availability of Performance Best Practices for vSphere 5.1.  This is a book designed to help system administrators obtain the best performance from vSphere 5.1 deployments.

The book addresses many of the new features in vSphere 5.1 from a performance perspective.  These include:

• Use of a system swap file to reduce VMkernel and related memory usage
• Flex SE linked clones that can relinquish storage space when it’s no longer needed
• Use of jumbo frames for hardware iSCSI
• Single Root I/O virtualization (SR-IOV), allowing direct guest access to hardware devices
• Enhancements to SplitRx mode, a feature allowing network packets received in a single network queue to be processed on multiple physical CPUs
• Enhancements to the vSphere Web Client
• VMware Cross-Host Storage vMotion, which allows virtual machines to be moved simultaneously across both hosts and datastores

We’ve also updated and expanded on many of the topics in the book.

These topic include:

• Choosing hardware for a vSphere deployment
• Power management
• Configuring ESXi for best performance
• Guest operating system performance
• vCenter and vCenter database performance
• vMotion and Storage vMotion performance
• Distributed Resource Scheduler (DRS), Distributed Power Management (DPM), and Storage DRS performance
• High Availability (HA), Fault Tolerance (FT), and VMware vCenter Update Manager performance
• VMware vSphere Storage Appliance (VSA) and vCenter Single Sign on Server performance

The book can be found at: http://www.vmware.com/pdf/Perf_Best_Practices_vSphere5.1.pdf.

At the vSphere 5.1 release time frame, the 16Gb Fibre Channel fabric and 16Gb FC cards have become generally available. The release of the 16Gb FC driver on the VSphere platform can now take full advantage of the new 16Gb FC HBA and thus have better storage I/O performance.

As described in the paper “Storage I/O Performance on vSphere 5.1 over 16Gb Fibre Channel”, the storage I/O throughput has doubled for the larger block I/Os compared to the 8Gb FC. In the paper it uses single storage I/O worker to show the throughput has improved with better CPU efficiency per I/O. For random I/Os in small block sizes, 16Gb FC can attain much higher I/Os per second than a 8Gb FC connection.

The VMware vSphere I/O performance team has published a paper that shows VXLAN performance on vSphere 5.1. Virtual extensible LAN (VXLAN) is a network encapsulation mechanism that enables virtual machines to be deployed on any physical host, regardless of the host’s network configuration.

The paper shows how VXLAN is competitive in terms of performance when compared to a configuration without VXLAN enabled. The paper describes the test results for three experiments: throughput for large and small message sizes, CPU utilization for large and small message sizes, and throughput and CPU utilization for 16 virtual machines with various message sizes. Results show that a virtual machine configured with VXLAN achieved similar networking performance to a virtual machine without VXLAN configured, both in terms of throughput and CPU cost. Additionally, vSphere 5.1 scales well as more virtual machines are added to the VXLAN network. Read the full paper here.

Hadoop provides a platform for building distributed systems for massive data storage and analysis. It has internal mechanisms to replicate user data and to tolerate many kinds of hardware and software failures. However, like many other distributed systems, Hadoop has a small number of Single Points of Failure (SPoFs). These include the NameNode (which manages the Hadoop Distributed Filesystem namespace and keeps track of storage blocks), and the JobTracker (which schedules jobs and the map and reduce tasks that make up each job). VMware vSphere Fault Tolerance (FT) can be used to protect virtual machines that run these vulnerable components of a Hadoop cluster. Recently a cluster of 24 hosts was used to run three different Hadoop applications to show that such protection has only a small impact on application performance. Various Hadoop configurations were employed to artificially create greater load on the NameNode and JobTracker daemons. With conservative extrapolation, these tests show that uniprocessor virtual machines with FT enabled are sufficient to run the master daemons for clusters of more than 200 hosts.

A new white paper, “Protecting Hadoop with VMware vSphere 5 Fault Tolerance,” is now available in which these tests are described in detail. CPU and network utilization of the protected VMs are given to enable comparisons with other distributed applications. In addition, several best practices are suggested to maximize the size of the Hadoop cluster that can be protected with FT.

vMotion and Storage vMotion are key, widely adopted technologies which enable the live migration of virtual machines on the vSphere platform. vMotion provides the ability to live migrate a virtual machine from one vSphere host to another host, with no perceivable impact to the end user. Storage vMotion technology provides the ability to live migrate the virtual disks belonging to a virtual machine across storage elements on the same host.  Together, vMotion and Storage vMotion technologies enable critical datacenter workflows, including automated load-balancing with DRS and Storage DRS, hardware maintenance, and the permanent migration of workloads.

Each vSphere release introduces new vMotion functionality, increased reliability and significant performance improvements. vSphere 5.1 continues this trend by offering new enhancements to vMotion that provide a new level of ease and flexibility for live virtual machine migrations.  vSphere 5.1 vMotion now removes the shared storage requirement for live migration and allows combining traditional vMotion and Storage vMotion into one operation. The combined migration copies both the virtual machine memory and its disk over the network to the destination vSphere host. This shared-nothing unified live migration feature offers administrators significantly more simplicity and flexibility in managing and moving virtual machines across their virtual infrastructures compared to the traditional vMotion and Storage vMotion migration solutions.

A new white paper, “VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices”, is now available. In that paper, we describe the vSphere 5.1 vMotion architecture and its features. Following the overview and feature description of vMotion in vSphere 5.1, we provide a comprehensive look at the performance of live migrating virtual machines running typical Tier 1 applications using vSphere 5.1 vMotion, Storage vMotion, and vMotion. Tests measure characteristics such as total migration time and application performance during live migration. In addition, we examine vSphere 5.1 vMotion performance over a high-latency network, such as that in a metro area network. Test results show the following:

• During storage migration, vSphere 5.1 vMotion maintains the same performance as Storage vMotion, even when using the network to migrate, due to the optimizations added to the vSphere 5.1 vMotion network data path.
• During memory migration, vSphere 5.1 vMotion maintains nearly identical performance as the traditional vMotion, due to the optimizations added to the vSphere 5.1 vMotion memory copy path.
• vSphere 5.1 vMotion retains the proven reliability, performance, and atomicity of the traditional vMotion and Storage vMotion technologies, even at metro area network distances.

Finally, we describe several best practices to follow when using vMotion.

For the full paper, see “VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices”.

We recently worked with EMC's internal IT organization to study the performance of their largest Oracle RAC instance on vSphere 5.  The results revealed that Oracle RAC, when virtualized with vSphere 5, performed within 7% on average of a corresponding physical environment. The chart below highlights the results from these tests.  

The blue bars are for tests done at a regular level of load and the green bars are for tests done at a 2x level of load.  Results are reported in terms of sum total response time in seconds for the variety of different transactions in the tested workload.

For full details about the tests please refer to the paper – Performance Study of Oracle RAC on VMware vSphere 5.

This paper also provides the performance best practices developed and implemented for Oracle RAC on vSphere 5 for these tests. This information can be used to optimize existing and new installations of Oracle RAC on vSphere.