how to determine which processes are responsible for disk i/o

[Christiaan Kelly]

I am trying to determine which process(es) is (are) responsible for disk i/o. On a very lightly loaded system, I have some strange disk activity (according to sar -d, about 2MB/second). sar -u and top show me that no processes are very busy with CPU, so that doesn't help, and sar -d and iostat report only aggregate i/o for each disk.

Are there any standard commands or utilities which inform about disk i/o by individual processes rather than system-wide activity?
And if so, is it then possible to determine which files are heavily accessed (not just open which fuser gives, but open with heavy i/o)?

I have heard wonders about Glance. Unfortunately I don't currently have that utility.

[Rob Smith]

Go to http://hpux.cs.utah.edu/ and download a copy of lsof. It gives you a excellent details of what processes are doing on a system. The download is in sd format so it is easy to install. Hope this helps.

Rob Smith

[Thierry Poels_1]

Hi,
indeed Glance would be a great help.
There is a trial version on the HP-UX Application CD's. It's has all functionalities, but can only be used for 2/3 months.
good luck,
Thierry.

[Philip Chan_1]

Isn't it the kernel the only process that does disk I/O jobs? because all disk I/Os must be done by the "read" and "write" system calls.

~Philip

[Philip Chan_1]

Hi Chris,

In your case I think you really need glance for the job. With glance you can sort running process list by disk I/O rate, then the top process from the sorted list will be the one that you're looking for.

Rgds,
Philip

[Bill McNAMARA_1]

You can also have a look at PerfView which is also a free trial download and should give you exactly what you need.... and more.

Later,
Bill

[Vincenzo Restuccia]

http://hpux.cs.utah.edu/hppd/cgi-bin/search download lsof

[Vincenzo Restuccia]

http://hpux.cs.utah.edu/hppd/cgi-bin/search download lsof