Windows Server Performance Team Blog : Performance

File Server Capacity Tool (FSCT) 1.0

winsrvperf — Fri, 13 Nov 2009 19:06:00 GMT

What is “FSCT”?

New builds of Microsoft Windows are produced almost every day for internal development and testing. In order to detect performance regressions as soon as possible, those builds have to be evaluated and compared to their predecessors as well as previous public releases. A range of performance tests are used for these comparisons, including one called “FSCT” (which stands for File Server Capacity Tool). FSCT was developed by the Windows Server Performance team as a tool capable of simulating multiple concurrent users accessing a file server using CIFS/SMB/SMB2. Its architecture allows for usage of “workloads”. Each workload consists of a set of basic scenarios (e.g. upload of a file using Explorer, upload of a file using xcopy, Microsoft Word opening a file, etc.), information on how often those scenarios should be performed by users, and what files on the file server under test should be used. FSCT measures a file server’s capacity for a given workload. This includes the highest throughput the server can sustain and the maximum number of active users the server can support. FSCT also reports on server resource utilization, which can help identify performance bottlenecks such as network or storage bandwidth or CPU utilization.

The HomeFolders workload

The publically available version of “FSCT” comes with a single workload called HomeFolders. It was created by working with Microsoft IT administrators to capture Event Tracing for Windows (ETW) traces from real, heavily accessed file servers and their clients. The data included server side traces, client API traces and network traces, to capture the requests type distribution, parameters distribution, file set characteristics, and connection characteristics. Finally, the workload was created and tested to achieve approximately the same usage patterns found in the traces.

The workload development effort included creating the scenarios, creating the file sets and defining the number of runs per user per hour of each scenario. It is important to mention that “FSCT” and the HomeFolders workload were developed independently. The “FSCT” architecture allows for the creation of custom workloads and scenarios, as well as tweaking the existing workloads. However, as mentioned previously, only the HomeFolders is included in the initial release of “FSCT”.

You can find more information on FSCT at http://blogs.technet.com/josebda/archive/2009/09/16/file-server-capacity-tool-fsct-1-0-available-for-download.aspx

Performance Tuning Guidelines for Windows Server 2008 R2 Released

winsrvperf — Tue, 14 Jul 2009 20:34:00 GMT

With Windows Server 2008 R2 almost at RTM, a new tuning guide has been released. It can be found here.

And don't forget the Windows Server 2008 Turning Guide is still availiable and has recently been refreshed for SP2.

Windows Server Performance Team

Greater than 64 Logical Processor support on Windows Server 2008 R2

winsrvperf — Sat, 22 Nov 2008 04:19:00 GMT

In the past few weeks, there have been a number of new feature announcements around Windows 7 and Windows Server 2008 R2 at PDC and WinHEC conferences. From a Server perspective, Power Management, Virtualization, and Greater than 64 processor support are considered the top three features for Windows Server 2008 R2. I will focus on the greater than 64 processor support, given it is a new milestone for Windows, and sets up the stage for competing on much larger and higher end servers. The support enables large scale database customers to deploy their solutions on Windows and expect good scalability numbers. Of course, the scalability realized is highly dependent on the applications and drivers being able to scale well beyond 64 processors. To do so, application and driver developers are strongly encouraged to read up on the greater than 64 processor work here to see what has changed, and what type of code modifications are necessary to take full advantage of this new capability. The document describes the architecture, terminology, and goes into more details about the new APIs.

Ahmed Talat

Performance Manager

Windows Server Performance Team

Hyper-V and VHD Performance - Dynamic vs. Fixed

winsrvperf — Fri, 19 Sep 2008 21:08:00 GMT

My name is Tim Litton, I work as a Program Manager within the Microsoft Windows Server team, and my particular area of focus is performance optimization for Hyper-V.

With the recent release of Hyper-V, customers are starting to ask us how to configure Hyper-V to get the best performance. It’s generally recognized that there is overheard running a virtualized environment, but the question that really needs to be answered is how much?

With this in mind, I thought I’d share some of our recent testing of Hyper-V and how disk workloads perform when using Fixed or Dynamic VHDs. The goal here is to provide some data that backs up the tuning guidance that can be here: http://www.microsoft.com/whdc/system/sysperf/Perf_tun_srv.mspx.

The following graph shows the relative performances for a number of different scenarios (with Dynamic VHD being the baseline).

Fixed VHD always performs better than a Dynamic VHD in most scenarios by roughly 10% to 15% with the exception of 4k writes, where Fixed VHD performs significantly better.

We ran 16 virtual machines when performing these tests (see “How We Tested” below) with the goal of evaluating how well Hyper-V performed in the server consolidation scenario. Being able to consolidate a number of physical machines onto a single machine and have the virtual machines able to handle the load is a very important design goal for Hyper-V.

The exact result that a customer is going to see will depend on quite a few variables (e.g. how large and often the reads and writes are, how many outstanding I/O there can be at one time), so performing real-world testing is the best way to assess what impact virtualization will have.

Recently, QLogic published a benchmark for I/O throughput for storage devices going through Windows Server 2008 Hyper-V (http://www.qlogic.com/promos/products/hyper-v.aspx) that closely matches the native performance, thus demonstrating Hyper-V’s ability to bring the advantages of virtualization to large-scale datacenters.

How We Tested

Hardware: DP DL580 G5, 16 x 2.4 GHz (Intel E7340), 16 GB RAM

Disk: HP P800, 25 spindles

Virtual Machine Setup: 16 Virtual machines, each running Windows Server 2008 Enterprise Edition (64 bit), 1 CPU, 796 MB RAM

Testing Software: We used IO Meter (http://www.iometer.org) to generate the workload for the I/O system, with a maximum number of 8 outstanding I/Os per virtual machine to a 100MB file.

Power and Hyper-V are now part of the Windows Server 2008 Tuning Guide!

winsrvperf — Tue, 17 Jun 2008 22:58:00 GMT

The guide has been updated with sections on Power and Hyper-V guidelines and best practices. Check out the updated Tuning Guide and tell us what you think by following the feedback link at the top of the Tuning Guide. We look forward to hearing from you!

Ahmed Talat
Performance Manager
Windows Server Performance Team