How to determine what process is actively using my harddisk?

UNIX AIX
1

Hi,

Is there any command that I can issue to check who is actively using my harddisk? I notice that yesterday the hdisk0 and hdisk1 is really actively being used and is reaching almost 100%. I realized that this is because of paging which is climbing up to 70%.

However, just this morning I see paging is at 7% but still the hdisk0 and hdisk1 is high. Any thoughts?

Thanks.

2

You mean the %tm_act from iostat or other monitoring tools?
Best show us an excerpt of

iostat -d 1 20

while this peak/busy behaviour occurs. Also a

vmstat 1 20

might come handy.

You could use the too filemon to try to locate at least the LV(s) and file(s) that is/are affected.
Example from man page:

filemon -o fmon.out -O all

Best check the man page for it. When launching it you can stop it after some seconds or minutes of busy disk time with

trcstop

Should be also covered in the Performance Tools Redbook from IBM.
If you found the LV/FS or file you could also check with fuser or lsof which process might be related.

3

Hi zaxxon,

Thanks for the prompt reply. I will try this tomorrow.

4

Np, I added some info to my post that you might have missed reading it while I edited it again :slight_smile: