iostat - Linux I/O performance monitoring utility

iostat is a command line I/O performance monitoring utility. It is present in almost every major Unix flavor in use today, and here you can get the version for Linux.

It works on both 2.4 & 2.6. What makes it different from other Linux utilities, which mostly show only I/O transfer rates, is that you finally can get important information about disk utilization, number of requests, average queue size and disk & queue wait times. No serious sysadmin should be without it. Check the screenshots to learn more.

How fast is your disk?

Binary Data iostat-2.2.tar.gz12.87 KB


On Gentoo: emerge app-admin/sysstat

On Debian (as root): apt-get install sysstat

Note this iostat and the one in sysstat package are not the same thing.

While iostat is a fine tool, my main hang up is it only shows what my disk is doing when I want to see what the rest of my system is doing at the same time! I want to log the data to a file in the background and look at it later. I may even want to plot the data and that's why I wrote collectl, which I think can replace just about every other monitoring tool and provide a single, consistent view of what your system is doing in one place. here's a few example of the types of output it can generate:

I even put together a matrix that maps existing commands onto collectl ones at:

but don't take my word for it, download it and take it for a spin...


Can you point me to the download site of your "collect" tool, please? Thanks.

am excited to work with this provide the url to download

Interested in seeing what and how this tool collects stats


Monitoring the system IO is not an easy task. Because sometimes its very difficult to even find the process which is taking the io. Some process can eat the whole system io that the processor will go to wait on io state..And many application will be in a kind of stale state.

the above link explains the whole IO concept in depth..