Re: I/O performance measurement tools on Linux

[Douglas Gilbert <dougg@torque.net>]

Ju, Seokmann wrote:
> Hi,
> 
> Are there any performance measurement tools available that running on
> Linux?
> I would like to measure disk I/O performance (file system and raw I/O)
> on several kernels.
> Please lead me to the place.

The sg3_utils package may help with some raw SCSI
and SATA disk I/O measurements.
sg_dd, sgp_dd and sgm_dd are dd variants that
let you tweak a lot of low level details. The sg_read
utility can be used to measure disk cache throughput,
transport speeds and command overhead.

Recently I have been looking at measuring command overhead.
On the disks that I am testing a zero block READ (i.e.
issue a SCSI READ for zero blocks) is the fastest command.

The most recent released sg3_utils can be found at:
http://www.torque.net/sg   [Utilities section]
The latest beta is in the news section of that page.
A description can be found at:
http://www.torque.net/sg/u_index.html

Doug Gilbert