How to use vdbench for create random data files

 Vdbench is a controlled I/O load simulation tool for storage systems developed by oracle as an open source.

•  It works with Linux and Windows 
• Written in Java and C

Vdbench has three basic definitions in the configuration file.

• SD or storage definition: This defines what storage to use for the testing.
• WD or workload definition: This defines the workload parameter for the testing.
• RD or run definition: This defines storage, workload and run duration.

Storage definition

SD defines the storage used for the testing. Make sure you select the right storage or else everything on the selected disk could get destroyed. The SD name should be unique.

sd=default,size=100g

sd=sd1,lun=/dev/sdb0

sd=sd2,lun=/dev/sdb1,size=100g

sd=sd3,lun=/dev/sdb2,size=200g

Workload definition

WD defines the workload used by the script for testing. The WD name must be unique.

WD parameters include the following:

sd – Test device

seekpct – Percentage time to move location

rdpct – Read percentage

xfersize – Transfer size

skew – Percentage of skew this workload receives from the total I/O rate

wd – Default setup for the workload

threads – How many concurrent operations for this workload

hotband – Executes hot band workload against a range of storage

wd=hotwd_uniform,skew=6,sd=sd*,seekpct=100,rdpct=50 wd=hotwd_hot1,sd=sd*,skew=28,seekpct=rand,hotband=(10,18)

Run definition

RD defines what storage and workload will be run together and for how long. Each run definition name must be unique.

RD parameters include:

wd – Workload load definition

iorate – Either IOPS

warmup – Warm-up time that will be excluded from the elapsed time (10s/2m/1h)

elapsed – How long to run

interval – Stats collection interval

threads – Number of threads

forrdpct – Range of percentage read to execute

rd=rd1_hband,wd=HOTwd*,iorate=MAX,warmup=30,elapsed=6H,interval=10,pause=30,th=200 rd=rd1_seq,wd=wd_seq,iorate=max,forrdpct=(0,100),xfer=256K,warmup=30,el=20m,in=5,th=20

1.Download vdbench from oracle site : 

 Vdbench Downloads (oracle.com)

2.copy the zip file to windows/linux.

3.Insall JAVA on windows/linux

4.Once extract the files you can find there will be example7 config file: edit the config file as per your req:

file:example7:

 vdbench50407]# cat example7

*

* Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

*

*

* Author: Henk Vandenbergh.

*

*Example 7: File system testing

fsd=fsd1,anchor=/dir1,depth=2,width=2,files=2,size=100g

fwd=fwd1,fsd=fsd1,operation=read,xfersize=4k,fileio=sequential,fileselect=random,threads=2

rd=rd1,fwd=fwd1,fwdrate=100,format=yes,elapsed=10,interval=1

*

* This parameter file will use a directory structure of 4 directories and 8 files

* The RD parameter 'format=yes' causes the directory structure to be completely

* created, including initialization of all files to the requested size of 128k.

* After the format completes the following will happen for 10 seconds at a rate

* of 100 reads per second:

*         Start two threads (threads=2; 1 thread is default).

*         Each thread:

*         Randomly selects a file (fileselect=random)

*         Opens this file for read (operation=read)

*         Sequentially reads 4k blocks (xfersize=4k) until end of file (size=128k)

*         Closes the file and randomly selects another file.

*

*

* Directory structure:

*

* find dir1 | grep file

5.run the script now:

./vdbench -f example7