Total amount of system memory

[panks]

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

[sujit kumar singh]

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]

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

[panks]

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]

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

[bibith dathan]

Hi

Please post more details of application which running on server .

Bibith

[Jeeshan]

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

[Dennis Handly]

>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]

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]

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]

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

[panks]

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]

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

[Dennis Handly]

>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]

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

[panks]

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]

please paste the output of glance/top showing process based memory utilization