HPE Community read-only access December 15, 2018
This is a maintenance upgrade. You will be able to read articles and posts, but not post or reply.
Hours:
Dec 15, 4:00 am to 10:00 am UTC
Dec 14, 10:00 pm CST to Dec 15, 4:00 am CST
Dec 14, 8:00 pm PST to Dec 15, 2:00 am PST
System Administration
cancel
Showing results for 
Search instead for 
Did you mean: 

Total amount of system memory

 
panks
Regular Advisor

Total amount of system memory

Hi,

My system is having 64GB of total memory and when I checked with glance -m I found that system is consuming more than 10GB of memory.
Can you please suggest how this can be reduced or is this the standard:

Total VM : 30.3gb Sys Mem : 10.4gb User Mem: 33.5gb Phys Mem: 63.7gb
Active VM: 26.1gb Buf Cache: 6.4gb Free Mem: 13.5gb
16 REPLIES
sujit kumar singh
Honored Contributor

Re: Total amount of system memory

it is showing that 10 GB of the entire memory that ur system has is being used as a SYSTEM Memory that is the memory that has been reserved for the System Processes for HP-UX ...


do a

#dmseg| grep -i physical


what does that show, that is teh actual memory Physically installed in ur server.


alao u can see memory amount installed as in

do the cstm commsnd

#cstm
cstm>sel all
cstm>info;wait
cstm>infolog


and u can see the Memory Specications at the end of this display.





do not fprget to assign points please.


Regards
Sujit
Javed Khan_1
Valued Contributor

Re: Total amount of system memory

Hi,

Check dbc_min_pct and dbc_max_pct if set to 5 and 50 (default)

set it to dbc_min_pct=3 & dbc_max_pct=5


Javed
Never Give Up
panks
Regular Advisor

Re: Total amount of system memory

Thanks but when I checked dbc_max_pct and dbc_min_pct its value is 10 and 5 resp.

And the usage of dbc_max_pct is 100% so reducing the value of it may cause problem.

Please suggest. I want to know that out 0f 64 GB that reserved ~11GB for system is that standard value. I mean 25% of total memory, or it can be changed.
Steven E. Protter
Exalted Contributor

Re: Total amount of system memory

Shalom,

swapinfo -tam is fairly easier to understand.

It also shows swap.

This figure: Phys Mem: 63.7gb
Shows the system is recognizing all physical memory.

The way I see your display, is system memory, which includes SGA and scuh use is 33.5 gb, the system memory, for OS and such is using a surprisingly high 10.4 GB, but that figure depends on what services you have running.

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com

Re: Total amount of system memory

Hi

Please post more details of application which running on server .

Bibith
Jeeshan
Honored Contributor

Re: Total amount of system memory

no actually you need to calculate the dbc parameters according to your physical memory.

your parameter is already set to *_max = 10 then try to monitor which system processes are consuming more memory.

check with this command

#export UNIX95=1;ps -ef -o comm,pcpu,vsz,args |more
a warrior never quits

Re: Total amount of system memory

>ahsan: export UNIX95=1;ps -ef -o comm,pcpu,vsz,args

You don't want to export UNIX95, you just want it temporary:
UNIX95=EXTEMDED_PS ps -ef -o comm,pcpu,vsz,args
panks
Regular Advisor

Re: Total amount of system memory

Thanks for your reply but the system memory is constant since we configured the system that is 10.4 GB. One more thing as dbc_max_pct was set to 10 it was 100% utilized so I have changed the value of dbc_max_pct to 25. Please suggest how we can reduce the value of system memory or is it the standard value I mean 25% of total memory.
TTr
Honored Contributor

Re: Total amount of system memory

So a lot of your memory is used up for kernel buffer cache. Normally you don't need taht much buffer cache. For a server like yours I would chose min 1% and max 2% or at most 2%min and 4% max. The buffer cache will always be at 100% if the server is busy.

Now for the system memory, 10.4GB out of the 64GM mmeory is about 15%. That 's probably normal for a busy server and the newer itanium servers. It all depends what the kernel is doing, a lot of new i/o, paging etc. Need to look further in the process activity as already mentioned.
Steven E. Protter
Exalted Contributor

Re: Total amount of system memory

Shalom again:

One more thing as dbc_max_pct was set to 10 it was 100% utilized so I have changed the value of dbc_max_pct to 25. Please

That uses a lot of space for the buffer pool.

I normally use 5 and 7 (max) on an Oracle based system. For 11.11 and below buffer pool increase does not help with Oracle performance anyway.

Changing the buffer pool is extremely expensive for a system in terms of performance. Having those numbers so far apart is bad for overall systems performance.

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
panks
Regular Advisor

Re: Total amount of system memory

Thanks Steve!! So you mean I should revert back the value of dbc_mac_pct to 10%. One more question is this parameter only responsible for oracle. And is going to create any problem if utilization of dbc_max_pct is continously at 100% because user has already faced a problem one time and their entire oracle instance hung.
panks
Regular Advisor

Re: Total amount of system memory

Ok I have reduced the value of dbc_max_pct now but still the buf cache is at same value.

Re: Total amount of system memory

>I have reduced the value of dbc_max_pct now but still the buf cache is at same value.

Which? Size or percent? For the former, it may take some time to reduce it.
Javed Khan_1
Valued Contributor

Re: Total amount of system memory

Also check with dba if kernel tuning is correct with respect to the oracle version running on your system , or may be they need to so some performance tuning at db end
Never Give Up
panks
Regular Advisor

Re: Total amount of system memory

What does that mean, do you mean to say if there is not proper tuning at DBA end then system memory will consume more.
Is there any way by which I can cut down the usage of this big amount of system memory and free up it for the use of user processes.

Thanks
Javed Khan_1
Valued Contributor

Re: Total amount of system memory

please paste the output of glance/top showing process based memory utilization
Never Give Up