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System memory usgae

 
Steve Lee_7
Occasional Advisor

System memory usgae

Hi

I have an rp4440 server with 1 GHz * 4 CPU and 10GB memory
I noticed that system memory usage is about 4GB/10GB total memory on glance
Customer asked me to reduce system memory size
Is there anyway to resize system memory size?
I need to explain what root cause is


6 REPLIES 6
A. Clay Stephenson
Acclaimed Contributor

Re: System memory usgae

You want root cause and supply essentially zero data? The most probable cause is the default dbc_mac_pct value of 50% which controls the size of the dynamic buffer cache. You should reduce dbc_max_pct to no more than 15% and dbc_min_pct to about 5%. You may also have other tunables that are badly set but the most likely are the buffer cache tunables.
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inventsekar_1
Respected Contributor

Re: System memory usgae

Lee, As clay told, it is always better to give *more than enough* information.

reply datas like, what applications u r running, is it a production system or going to be production soon, also, check the memory usage with other tools also...[** glance may be wrong sometimes(i think)**]

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Steve Lee_7
Occasional Advisor

Re: System memory usgae

I have checked the buffer cache size
It is less than 1GB

Here is memory status on glance and screen shot

Total VM : 7.62gb Sys Mem : 3.83gb User Mem: 5.20gb Phys Mem: 10.0gb
Active VM: 7.56gb Buf Cache: 819.0mb Free Mem: 172.5m
Michael Steele_2
Honored Contributor

Re: System memory usgae

The problems not with your system memory utilization its with your application memory utilization. Can you provide what's running atop the O/S? SAP, Oracle?

I've attached a script for you to look at and run. Can you paste in the values of the kernel parms. listed in this script?
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rayche
Frequent Advisor

Re: System memory usgae

Pls try to reduce vx_ninode parameter, in fact , HPUX use VXFS, and VXFS use its own parameter "vxfs_ninode" to keep a large cache in system memory , you can reduce it and the system memory will release, pls do it as following :
1. Find the default number of vxfs_ninode
echo "vxfs_ninode"|adb /stand/vmunix /dev/mem

2. Adjust the parameter to 20000 if your machine is not file server

SAM--->vx_ninode=20000

Thanks.

RayChe
rayche
Frequent Advisor

Re: System memory usgae

Sorry , to the first step,the correct is :

echo "vxfs_ninode/D"|adb /stand/vmunix /dev/mem