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Big Files Lots of Little File Processing Benchmarking with Vdbench

February 2, 2016 – 10:48 pm

Big Files Lots of Little File Processing Benchmarking with Vdbench

server storage I/O trends

Need to test a server, storage I/O networking, hardware, software, services, cloud, virtual, physical or other environment that is either doing some form of file processing, or, that you simply want to have some extra workload running in the background for what ever reason?

I/O performance

Getting Started

Here’s a quick and relatively easy way to do it with Vdbench (Free from Oracle). Granted there are other tools, both for free and for fee that can similar things, however we will leave those for another day and post. Here’s the con to this approach, there is no Uui Gui like what you have available with some other tools Here’s the pro to this approach, its free, flexible and limited by your creative, amount of storage space, server memory and I/O capacity.

If you need a background on Vdbench and benchmarking, check out the series of related posts here (e.g.

Get and Install the Vdbench Bits and Bytes

If you do not already have Vdbench installed, get a copy from the Oracle or Source Forge site (now points to Oracle here).

Vdbench is free, you simply sign-up and accept the free license, select the version down load (it is a single, common distribution for all OS) the bits as well as documentation.

Installation particular on Windows is really easy, basically follow the instructions in the documentation by copying the contents of the download folder to a specified directory, set up any environment variables, and make sure that you have Java installed.

Here is a hint and tip for Windows Servers, if you get an error message about counters, open a command prompt with Administrator rights, and type the command:

$ lodctr /r

The above command will reset your I/O counters. Note however that command will also overwrite counters if enabled so only use it if you have to.

Likewise *nix install is also easy, copy the files, make sure to copy the applicable *nix shell script (they are in the download folder), and verify Java is installed and working.

You can do a vdbench -t (windows) or ./vdbench -t (*nix) to verify that it is working.

Vdbench File Processing

There are many options with Vdbench as it has a very robust command and scripting language including ability to set up for loops among other things. We are only going to touch the surface here using its file processing capabilities. Likewise, Vdbench can run from a single server accessing multiple storage systems or file systems, as well as running from multiple servers to a single file system. For simplicity, we will stick with the basics in the following examples to exercise a local file system. The limits on the number of files and file size are limited by server memory and storage space.

You can specify number and depth of directories to put files into for processing. One of the parameters is the anchor point for the file processing, in the following examples =S:\SIOTEMP\FS1 is used as the anchor point. Other parameters include the I/O size, percent reads, number of threads, run time and sample interval as well as output folder name for the result files. Note that unlike some tools, Vdbench does not create a single file of results, rather a folder with several files including summary, totals, parameters, histograms, CSV among others.

Simple Vdbench File Processing Commands

For flexibility and ease of use I put the following three Vdbench commands into a simple text file that is then called with parameters on the command line.



Simple Vdbench script

# SIO_vdbench_filesystest.txt
# Example Vdbench script for file processing
# fanchor = file system place where directories and files will be created
# dirwid = how wide should the directories be (e.g. how many directories wide)
# numfiles = how many files per directory
# filesize = size in in k, m, g e.g. 16k = 16KBytes
# fxfersize = file I/O transfer size in kbytes
# thrds = how many threads or workers
# etime = how long to run in minutes (m) or hours (h)
# itime = interval sample time e.g. 30 seconds
# dirdep = how deep the directory tree
# filrdpct = percent of reads e.g. 90 = 90 percent reads
# -p processnumber = optional specify a process number, only needed if running multiple vdbenchs at same time, number should be unique
# -o output file that describes what being done and some config info
# Sample command line shown for Windows, for *nix add ./
# The real Vdbench script with command line parameters indicated by !=




Big Files Processing Script

With the above script file defined, for Big Files I specify a command line such as the following.
$ vdbench -f SIO_vdbench_filesystest.txt fanchor=S:\SIOTemp\FS1 dirwid=1 numfiles=60 filesize=5G fxfersize=128k thrds=64 etime=10h itime=30 numdir=1 dirdep=1 filrdpct=90 -p 5576 -o SIOWS2012R220_NOFUZE_5Gx60_BigFiles_64TH_STX1200_020116

Big Files Processing Example Results

The following is one of the result files from the folder of results created via the above command for Big File processing showing totals.

Run totals

21:09:36.001 Starting RD=format_for_rd1

Feb 01, 2016 .Interval. .ReqstdOps.. ...cpu%... read ...write.... ..mb/sec... mb/sec .xfer.. ...mkdir... ...rmdir... ..create... ...close... ..delete...
rate resp total sys pct rate resp rate resp read write total size rate resp rate resp rate resp rate resp rate resp rate resp
21:23:34.101 avg_2-28 2848.2 2.70 8.8 8.32 0.0 0.0 0.00 2848.2 2.70 0.00 356.0 356.02 131071 0.0 0.00 0.0 0.00 0.1 109176 0.1 0.55 0.1 2006 0.0 0.00

21:23:35.009 Starting RD=rd1; elapsed=36000; fwdrate=max. For loops: None

07:23:35.000 avg_2-1200 4939.5 1.62 18.5 17.3 90.0 4445.8 1.79 493.7 0.07 555.7 61.72 617.44 131071 0.0 0.00 0.0 0.00 0.0 0.00 0.1 0.03 0.1 2.95 0.0 0.00

Lots of Little Files Processing Script

For lots of little files, the following is used.

$ vdbench -f SIO_vdbench_filesystest.txt fanchor=S:\SIOTEMP\FS1 dirwid=64 numfiles=25600 filesize=16k fxfersize=1k thrds=64 etime=10h itime=30 dirdep=1 filrdpct=90 -p 5576 -o SIOWS2012R220_NOFUZE_SmallFiles_64TH_STX1200_020116

Lots of Little Files Processing Example Results

The following is one of the result files from the folder of results created via the above command for Big File processing showing totals.
Run totals

09:17:38.001 Starting RD=format_for_rd1

Feb 02, 2016 .Interval. .ReqstdOps.. ...cpu%... read ...write.... ..mb/sec... mb/sec .xfer.. ...mkdir... ...rmdir... ..create... ...close... ..delete...
rate resp total sys pct rate resp rate resp read write total size rate resp rate resp rate resp rate resp rate resp rate resp
09:19:48.016 avg_2-5 10138 0.14 75.7 64.6 0.0 0.0 0.00 10138 0.14 0.00 158.4 158.42 16384 0.0 0.00 0.0 0.00 10138 0.65 10138 0.43 10138 0.05 0.0 0.00

09:19:49.000 Starting RD=rd1; elapsed=36000; fwdrate=max. For loops: None

19:19:49.001 avg_2-1200 113049 0.41 67.0 55.0 90.0 101747 0.19 11302 2.42 99.36 11.04 110.40 1023 0.0 0.00 0.0 0.00 0.0 0.00 7065 0.85 7065 1.60 0.0 0.00

Where to learn more

Which Enterprise Hard Disk Drives (HDD's) to use with a Content Server Platform

Oracle Vdbench resource page (downloads, documentation and other items)
Vdbench user forum


What this all means

The above examples can easily be modified to do different things particular if you read the Vdbench documentation on how to setup multi-host, multi-storage system, multiple job streams to do different types of processing. This means you can benchmark a storage systems, server or converged and hyper-converged platform, or simply put a workload on it as part of other testing. There are even options for handling data footprint reduction such as compression and dedupe.

Ok, nuff said (for now)



Greg Schulz - Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press) and Resilient Storage Networks (Elsevier)
twitter @storageio
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