topic Re: Memory utilisation high in Operating System - HP-UX

Memory utilisation high

Syedfurquan — Mon, 21 May 2012 08:31:51 GMT

Hello experts,

I am using HP-UX 11.31. I am facing performance issue on my server. When I check with glance it shows me memory utilisation always very high where as on the other hand CPU util, DISK util, Swap Util is less than 10% why so much difference. Is there is any memory leak? Also how to find using glance which process is using maximum memory.

Any hep will be very much appreciated.

Attaching a screenshot for the reference.

Regards

Re: Memory utilisation high

Duncan Edmonstone — Mon, 21 May 2012 08:52:50 GMT

Using all your available memory is a GOOD thing - memory costs money (I won't say it costs a lot of money as compared to a few years ago it doesn't), so having it actually utilised represents good value... would you rather have it sat there doing nothing?

Do you actually have an issue beyond "memory utilisation is high" - are your users complaining about performance problems or errors? If not, I seriously wouldn't worry...

Here's what I use to identify a "real" memory issue on 11.31:

1. Memory utilization above 95%

AND

2. Significant page-out activity (small amounts of page-out activity are usually filesystem cache data being flushed to disk)

AND

3. Device swap being used (not pseudo-swap)

If you don't see all 3 of those issues, I doubt you are really under memory pressure.

Re: Memory utilisation high

Dennis Handly — Mon, 21 May 2012 09:04:00 GMT

What does "swapinfo -tam" show?

Re: Memory utilisation high

Syedfurquan — Mon, 21 May 2012 11:21:19 GMT

Hi Duncan & dennis,

Thanks for the reply. As per your query regarding memory utilisation please find my answer:

1. Memory utilization above 95%

It is not above 95% but it is somewhere around that only.

2. Significant page-out activity (small amounts of page-out activity are usually filesystem cache data being flushed to disk)

Yes page out activity is very low. Please find glance O/p below:

--------------------------------------------------------------------------------
MEMORY REPORT Users= 1
Event Current Cumulative Current Rate **bleep** Rate High Rate
--------------------------------------------------------------------------------

Page Faults 1917 13067 368.6 759.7 5371.4
Page In 0 4 0.0 0.2 1792.8
Page Out 0 0 0.0 0.0 0.0
KB Paged In 0kb 16kb 0.0 0.9 45.6
KB Paged Out 0kb 0kb 0.0 0.0 0.0

3. Device swap being used (not pseudo-swap)

No device swap is not being used.

swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 8192 0 8192 0% 0 - 1 /dev/vg00/lvol2
dev 8192 0 8192 0% 0 - 1 /dev/vg00/swapvol
reserve - 2253 -2253
memory 7761 5173 2588 67%
total 24145 7426 16719 31% - 0 -

The problem is faced by the end user. This is an application server. So when the user want to access the webpage, after entering their credentials it takes sometime 20-25minutes to fetch the details.

Regards

Re: Memory utilisation high

Dennis Handly — Mon, 21 May 2012 19:23:49 GMT

>after entering their credentials it takes sometime 20-25 minutes to fetch the details.

Do you have CPU and I/O stats during this time?

Where is the data stored? An Oracle database?

Re: Memory utilisation high

Syedfurquan — Tue, 22 May 2012 05:47:50 GMT

Hi,

Not really very high CPU or I/O stats.

Yes it is an oracle database.

Re: Memory utilisation high

西北男人 — Thu, 31 May 2012 15:57:27 GMT

I just run into the same problems