I'm just wondering what folks are using to benchmark/tune large arrays these days. I've always used bonnie with file sizes 2-3 times physical RAM. Maybe there's a better way?
Cheers,
chrism@imntv.com wrote:
Depends on your needs. You want to simulate as close as possible your intended application.
A lot of the commonly used tests such as bonnie/bonnie++ proved inappropriate when you want sync behaviour. I don't know about now but bonnie did not do fsync calls and so performance was better with it than real world performance for cases where fsync was used in the application.
To all on the list needing a disk test program:
I just uploaded this source file so I could share it with the list:
http://www.integratedsolutions.org/downloads/disktest.c
The link above is a program we use for testing disks and RAID arrays.
You will need to compile it on your linux system.
gcc -O2 disktest.c -o disktest
The program will allow for multiple loops, different number of 1 GB files and will even test your array to find the fastest write size between 512 bytes and 1 MB.
Reading the source will show that we used fsync. The program gets realistic meaningful results. It also allows for reading every sector on a disk or an array so that the storage can be thoroughly tested before going into production. (zcav like function)
The help looks like this:
Disktest, Version 2.02, integratedsolutions.org, GNU GPL This program tests the disk read and write speeds USAGE: disktest [options] Options: -l loops number of times to loop the program (default=1), -g gigs number of gigs to use (1 file per GB) (default=1); -t test have program determine buffer read/write size (default=8192); -z run zcav mode (read 100 meg chunks from user defined file); -f file_name file or device to read from when in zcav mode; -V display version and exit; -h display this help and exit.
It also has a looping zcav type function for testing new arrays multiple times.
The command line for this would look like:
disktest -l6 -z -f /dev/sda
This will read sda from the beginning to the end, 6 times
The performance test output is much more readable than bonnie++ (thats why we wrote it) and it will average the times from different loops and give you an average read and write speed.
Make sure you use a -g option that is at least 50% bigger than the amount of RAM in the machine. IE: 4 GB of RAM in the machine -> use -g6 or higher.
A typical command line looks like (machine has 4GB RAM)
disktest -t -g6 -l4
This will write and read 6 x 1GB files in the local directory, it will test for the fastest write buffer size and it will do 4 loops of this test and average the results.
Let me know if you have questions about it.
Seth Bardash
Integrated Solutions and Systems 1510 Old North Gate Road Colorado Springs, CO 80921
719-495-5866 719-495-5870 Fax 719-337-4779 Cell
http://www.integratedsolutions.org
Failure can not cope with knowledge and perseverance!
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chrism＠imntv.com -
Feizhou -
Joshua Baker-LePain -
Seth Bardash