topic Kernel memory usage in 11.31 in Operating System - HP-UX

Kernel memory usage in 11.31

Vladimir_Krut — Sat, 19 Feb 2011 16:42:21 GMT

Hello,
Newly installed system (11.31) used up to 50% of memory (total memory installed 32GB), I have oracle on it and nearly 1T file system,

Here is kmeminfo output
Physical memory usage summary (in page/byte/percent):

Physical memory = 8379648 32.0g 100%
Free memory = 2472962 9.4g 30%
User processes = 1946627 7.4g 23% details with -user
Detached SHMEM = 7 28.0k 0% details with -shmem
System = 3960489 15.1g 47%
Kernel = 2887362 11.0g 34% kernel text and data
Dynamic Arenas = 1896620 7.2g 23% details with -arena
misc region are = 241007 941.4m 3%
spinlock_arena = 222280 868.3m 3%
FCACHE_ARENA = 203505 794.9m 2%
reg_fixed_arena = 149003 582.0m 2%
vx_global_kmcac = 117055 457.2m 1%
Other arenas = 963770 3.7g 12% details with -arena
Super page pool = 469223 1.8g 6% details with -kas
Emergency pool = 17045 66.6m 0% system critical reserve
UAREA's = 9624 37.6m 0%
Static Tables = 492097 1.9g 6% details with -static
pfdat = 409162 1.6g 5%
htbl2_0 = 65536 256.0m 1%
inode = 7412 29.0m 0%
text = 4810 18.8m 0% vmunix text section
bss = 1973 7.7m 0% vmunix bss section
Other tables = 3203 12.5m 0% details with -static
File Cache = 1073127 4.1g 13% details with -ufc
Can I reduce Kernel memory usage?

BR,
Vladimir

Re: Kernel memory usage in 11.31

P Arumugavel — Fri, 02 Sep 2011 19:22:27 GMT

hi,

Changing the size using by kernl may lead to unexpected behaviour of system/application.

Steven: "Perhaps take a look at kernel high water marks from Glance/gpm before making any changes. Also check the kernel minimums from your applications. Oracle needs its kernel parameters"

Read the below threads to go for proceed.

http://h30499.www3.hp.com/t5/System-Administration/high-kernel-memory-usage/m-p/4437412#M356675

http://h30499.www3.hp.com/t5/General/Physical-memory-usage-of-kernel/m-p/4198418#M134907

http://h30499.www3.hp.com/t5/System-Administration/High-System-or-Kernel-Memory-Usage/m-p/4592005#M374982

Rgds...

Re: Kernel memory usage in 11.31

Venkatesh BL — Mon, 21 Feb 2011 05:19:32 GMT

Hi,

> Free memory = 2472962 9.4g 30%

You still have enough memory to keep things moving along. In case you get to low memory situation, the kernel daemon would kick in aggressively and free up whatever it can from various 'caches'.

Re: Kernel memory usage in 11.31

Vladimir_Krut — Mon, 21 Feb 2011 06:16:06 GMT

hi,

I think i need to rephrase the question,
is it normaly that system use up to 50% of memory when user's usage not greater than 25?

I have checked kernel parameters, and don't found the cause

Re: Kernel memory usage in 11.31

Jose Mosquera — Mon, 21 Feb 2011 09:56:04 GMT

Hi,

Have you checked with your DBA about the size of the System Global Area (SGA) for Oracle's instance?

Rgds.