Increase in RAM will effect SAP and DB Buffers or not??

[Former Member]

Hi,

i have installed ECC 6.0 on HP-UX IA64 with 3GB RAM, the performance is

bad as all the swap space (12 GB) and RAM is 100% used.we have added extra

3 GB RAM and 8 GB swap space but sill the performance remained same, should i manually increase the DB buffers or do i need to configure anything ??

Please advice me.

Thanks

Naren

[Former Member · Accepted solution]

Hi,

Check this for your HW and SW compatibilty

https://websmp101.sap-ag.de/quicksizing

https://websmp101.sap-ag.de/platforms

It will give you details about system requirement for particular component in your case, ECC6.0

IF you are using Oracle as a backend, see this note for memory issue

Note 789011 - FAQ: Oracle memory areas , good one for perf.tuning.

Note 113189 - Avoiding Shared Memory bottlenecks under HP-UX

see also Note 43427

Br,

Ami

Please rewards pts if suitable ans.

[Former Member · Accepted solution]

Hi Amit,

Thanks for the reply, when i increase the RAM after installation will it reflect buffers or still buffer sze remains same?? How can i manually increase the size of DB buffers ?

Thansk

Naren.

[Former Member]

Hello,

You have to manually change the oracle buffers via brtools or oracle client tool. And I would recommend you to also change the SAP buffers (extended memory, ...) via RZ10. This will also increase your performance.

Check ST02 to see if your SAP buffers are swapping.Check also that the Roll area/Paging area and extended memory in this report.

[Former Member]

Mate,

Space you have given is okai but in EEC 6 lot of table setting are not in buffer so u need to check the tables like

Tables:

DD01L

DD01T

DD02L

DD02T

DD03L

DD03T

DD04L

DD04T

DD05S

DD06L

DD06T

DD08L

DD08T

DD09L

SXC_ATTR

SXC_EXIT

SXS_INTER

Views:

DD02V

DD04V

DD05P

DD05Q

DD06V

V_EXT_COCO

V_EXT_M

V_EXT_S

Make the above table and view setting from SE11 -> technical setting and change it from buffer not allowed to buffer switched on

the performance will improve

Cheers

Arun

Award points for helpfull answer

[Former Member]

Hi,

The program sappfpar lets you check the minimum and maximum (worst case) swap space requirements for an SAP application server.

To check the instance profile for the SAP application server, start the SAP program sappfpar from the UNIX command line.

Enter the following command:

/usr/sap/<SYSTEM NAME>/SYS/exe/run/sappfpar check pf=/usr/sap/<SYSTEM NAME>/SYS/profile/<Profile name> nr=<System number> name=<Systemname> | more

The program generates a list. Note the total value for the shared memory in the field Shared memory under Memory requirements estimated. This value corresponds to the size of the shared memory required for this profile, and must be calculated into the shared memory requirements for the new Memory Management.

At the end of the list, the program specifies the minimum swap space requirements, the maximum heap memory requirements and the swap space requirements in a worst case scenario

Ensure that there is more swap space available than what is specified in the worst case scenario. (This is because non-SAP processes also require swap space.)

For optimal performance SAP recommends the following swap space:

20 GB on 64 bit systems

3-6 GB on 32 bit Linux

• Donot set the paging file on the drive where your physical Database files are existing as it will decrease the performance.Bcoz I/O activity is more on those disks .

Please award points if helpful

Regards,

Phani

[Former Member]

Hi,

Calculate the memory available:

This is the sum of the physical memory (RAM) and the available swap space. You can find both values in Transaction ST06 ("Physical memory" and "Swap space"):

Available memory = "Physical memory" + "Swap space".

Virtual memory required =

Data buffer: Size + Shared Pool: Size + 5 MB * (No. of work processes in the entire R/3 System) + 50 MB

Then change the relavant SAP buffer parameters and DB buffer Parameters

Regards,

Phani

[Former Member]

Hi Phani,

Thanks for the reply, were can i find DB Buffer size and Shared pool size?

Where and how can i set DB buffer new sizes??

thanks

Naren

[Former Member]

In Transaction ST04, SAP get these values from initSID.ora in the $ORACLE_HOME/dbs directory in unix.

Regards,

Phani

[Former Member]

Thanks, But how can reset the DB buffers in ST04.

[Former Member]

Hi,

Data buffer size is determined by the product of the block size (DB_BLOCK_SIZE (Oracle)) and the number of database block buffers specified in the init<SID>.ora parameter file .You cannot change it from SAP level.It should be done from Oracle level.

Regards,

Phani