topic Re: swap usage in Operating System - HP-UX

swap usage

yash123 — Mon, 11 Apr 2011 16:01:24 GMT

hello all,
swapinfo show swap device is 0% used while physical memeory is 100% utilised.
swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 18000 0 18000 0% 0 - 1 /dev/vg00/lvol2
reserve - 1134 -1134
memory 14798 14798 0 100%
total 32798 15932 16866 49% - 0 -

Any idea why swap not in use.
glance is not installed
Total Memory is 20GB

Re: swap usage

Dennis Handly — Mon, 11 Apr 2011 18:39:33 GMT

This is goodness, why are you worried?
If you get more of a load, you'll start to use swap.

Re: swap usage

yash123 — Wed, 13 Apr 2011 01:10:53 GMT

Thanks..
Could any body explain wny swapinfo report showing available memeory is 14GB and is 100% used.

Re: swap usage

Viktor Balogh — Wed, 13 Apr 2011 08:33:34 GMT

what does this command show you? post the output:

# echo "selclass qualifier memory;info;wait;infolog" | /usr/sbin/cstm

Re: swap usage

yash123 — Wed, 13 Apr 2011 10:01:16 GMT

Basic Memory Description

Module Type: MEMORY
Total Configured Memory : 20480 MB
Page Size: 4096 Bytes

Memory interleaving is supported on this machine and is ON.

Memory Board Inventory

DIMM Slot Size (MB)
--------- ---------
0A 2048
0B 2048
1A 2048
1B 2048
2A 2048
2B 2048
3A 2048
3B 2048
4A 1024
4B 1024
5A 1024
5B 1024
--------- ---------
System Total (MB): 20480

Re: swap usage

Viktor Balogh — Wed, 13 Apr 2011 10:09:42 GMT

man swapinfo -->

memory Memory paging area (also known as pseudo-swap).
This is the amount of system memory that can be
used to hold pages in the event that all of the
above paging areas are used up. See "Paging
Allocation" below. This line appears only if
memory paging is enabled.

Re: swap usage

Dennis Handly — Sat, 16 Apr 2011 10:55:18 GMT

>Could any body explain why swapinfo report showing available memory is 14GB and is 100% used.

Because that's how much pseudo-swap you have and that's how much is used. What is your real question and problem?

>Total Configured Memory: 20480 MB

What HP-UX version are you using? Depending on arcane formulas and actual kernel memory usage, pseudo-swap != RAM.

Re: swap usage

Vivek_Pendse — Fri, 22 Apr 2011 07:21:47 GMT

Hi,

You have 20GB installed physical memory in the system.
Every system has some threshold set for the memory. If the system is utilized more wrt memory & once it's threshold is reached, then the system will show you the % used in swap; else swap will be kept idle.
Hope this helps.

Thanks,
Vivek