Investigating intensive disk usage

[Mihails Nikitins]

Hi,

I see unusal high disk activity on an HP-UX system.

Could you suggest me hints to figure out what files are read/written to so much? What process reads/writes so much?

Thanks and points in advance!

BR,
Mihails

[RAC_1 · Accepted solution]

iostat 1 3
glance -i
Notive which file systems are getting hit high, then do lvdisplay and note down disks.
Check disk usages now
sar -d 2 10

glance -d will show you processes that using disk activity most. (top disk user id)

[Ranjith_5]

Hi,

sar -d 10 5

See the average disk usage at the end of the output. See the VG which contains the disk id showing high usage in the sar output.


Regards,
Syam

[Arunvijai_4]

Start with
# iostat -t 10 5
# glance

-Arun

[Morcos]

glance is a good utility for monitoring, you can use the trial software evaluation, it's on the application CD.

[Arunvijai_4]

You can download more performance related tools from,
http://h21007.www2.hp.com/dspp/dld/dld_DownloadsListingPage_IDX/1,2381,11169,00.html

-Arun

[Jean-Luc Oudart]

Also

are you paging out

swapinfo -tam

Regards
Jean-Luc

[Borislav Perkov]

Hi Mihails,

If you don't have glance try with

sar -d n m where n is number of sec for collection and m how many times you do that.
iostat -t n m. When using sar you need to pay attention on avwait and avserv parameters if they are high there is maybe device problem.

If on that device is swap than you can use swapinfo or vmstat n m page parameters.

You have to see which application use that disk, for example if it is raw device used by database.

Regards,
Borislav