Increase SAP instance capacity

[Former Member]

Hi all,

My system runs on ECC 6.0 EHP6. I have a distributed architecture with the Central Instance running on 1 host, the dialog instance running on another host and the database (oracle) instance also running on another host. The Central and Dialog servers have 8GB memory. All the memory parameters were set (by default) during installation. Now, I wish to increase the physical memory of the Central Instance to 16 GB and make it available to the instance. I want to know which parameters I need to change to make this possible. Please also suggest any other settings I need to verify/change.

regards.

[Reagan]

The 12+4 means 12 for SAP and 4 for the OS. In fact, I'll increase the physical memory to 16GB. (The database is already in a separate box).

If you increase the parameter em/initial_size_MB to 12GB then the Extended Memory requirement will change from 8184.0 MB to 12GB

Shared memory....................: 1732.0 MB
..in pool 10  114.3 MB,   93% used
..in pool 40  165.7 MB,   98% used
..not in pool: 1445.9 MB
Processes........................:  479.9 MB
Extended Memory .................: 8184.0 MB

The parameter em/initial_size_MB defines the value for EM during an SAP startup.

If you check this picture you will understand how it works.

http://help.sap.com/saphelp_nw2004s/helpdata/en/02/9626b3538111d1891b0000e8322f96/content.htm

http://help.sap.com/saphelp_nw2004s/helpdata/en/02/9626e7538111d1891b0000e8322f96/content.htm

I suggest you to increase the buffer parameters with hit ratio under 95% and then increase parameter em/initial_size_MB to 12GB and keep ztta/roll_extension to 4GB and run the sappfpar check against the test profile. Make corrections if there are errors.

Implement the solution on the main profile and restart the SAP system.

Regards

RB

[Reagan]

Hello Suraj

All I can say is create a test profile from the original instance profile like I suggested above and modify the memory parameters and also the buffer paramers I have mentioned above and then run sappfpar against the test profile.

cp -rp /sapmnt/P01/profile/P01_DVEBMGS01_sapvap01 /sapmnt/P01/profile/P01_DVEBMGS01_sapvap01_test

sappfpar check pf=/sapmnt/P01/profile/P01_DVEBMGS01_sapvap01_test

Regards

RB

[Former Member]

Hi,

From what i read.

Roll Area

The roll area is used for additional memory (if available) when the extended memory becomes full, as well as for the initial memory assigned to a user context. The limits are set using parameters.

Extended Memory

The large part of the user context is stored in the extended memory (EM). Page management of this memory stack is performed directly by the SAP system, and not by the operating system. This extended memory is implemented as an unnamed mapped file (on AIX and optionally on HP-UX as shared memory). This means the address space uses the paging file or uses the swap space of the operating system as background memory. For more information, please see the platform-specific documentation.

http://help.sap.com/saphelp_nwpi711/helpdata/en/49/325d57e93934ffe10000000a421937/frameset.htm

Just check the below PPT and you will find more details.

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CEAQFjAE&url=http%3A%2F%2Fas...

Thanks

Rishi Abrol

[former_member45419]

Hi Suraj,

check the below link

http://scn.sap.com/thread/3361244

http://scn.sap.com/thread/1488519

and pls check this notes  941735 - SAP memory management for 64-bit Linux systems

this parameter need to change ....1.em/initial_size_MB

                    2. Roll memory (ztta/roll_first),

                    3. Heap memory (abap/heap_area_nondia),

                    4. Roll memory (ztta/roll_area - ztta/roll_first),

                    5. Extended Memory (ztta/roll_extension(_nondia)).

Regards

Nayeem

[Former Member]

Hi all,

So the ABAP needs 12303.2 MB of memory in worst case, the worst case does it mean in peak periods? Also, SAP alone is requiring that much of memory, apart from the OS. So suppose for the OS we give some 4GB, then total would be (12+4) = 16GB, I'm I right?

In the first place, I'll try increase the em/initial_size_MB. What value would be appropriate?

regards.

[Former Member]

Hi,

Its not necessary that you need 12303.2. What i mentioned earlier that you had 1200 that was very low so you can start with 8gb and see .

Take the reference of the below note to set other parameters.

http://www.stechno.net/sap-notes.html?view=sapnote&id=88416

[RAM] = size of the physical main memory

[PM] = value of the profile parameter PHYS_MEMSIZE (standard value=[RAM])

[US] = maximum possible number of users (calculated from [PM])

Standard values for zero administration memory management

|Profile parameter      |Standard 32-bit|Standard 64-bit|Unit      |

|------------------------|---------------|------------------------|

|    em/initial_size_MB  |----    [PM]  |----    [PM]   |Mbyte     |

|---    em/max_size_MB  |---    20000  |---   100000   |Mbyte     |

|  em/address_space_MB  |-----    512  |-----   4096   |Mbyte     |

|----  ztta/roll_first  |-------    1  |-------    1   |Byte      |

|---    ztta/roll_area  |---  2000000  |---  3000000   |Byte      |

|  ztta/roll_extension  |  2000000000  |  2000000000   |Byte      |

|    abap/heap_area_dia  |  2000000000  |           2000000000   |Byte      |

| abap/heap_area_nondia  |  2000000000  |           0  |Byte      |

|  abap/heap_area_total  |  2000000000  |[PM]*1048576   |Byte      |

|-    rdisp/ROLL_MAXFS  |  [US] * 100   |  [US] * 100  |8KB-Block|

|---    rdisp/ROLL_SHM  |  [US] * 100   |  [US] * 100  |8KB-Block|

|---    rdisp/PG_MAXFS  |---    32768  |---    32768   |8KB Block |

|-----    rdisp/PG_SHM  |   [US] * 50  |   [US] * 50  |8KB-Block|

The default values were determined for a specific application mix that was oriented to the transaction mix for the SD benchmark.

Other note.

1612283 - Hardware Configuration Standards and Guidance

146289 - Parameter Recommendations for 64-Bit SAP Kernel

[Reagan]

Hello

You will need to take the worst case into consideration.

You need to consider the Memory assigned for the database as well.

The Note 88416 is valid for Windows systems.

Regards

RB

[Former Member]

Hi Rishi & RB,

I too agree that I need to consider the worst case scenario. So as I mentioned earlier, the database instance is on a separate host with 16 GB memory, I'll need only to consider the 12303.2 MB + memory for the OS, is this correct?

Based on the above, I think I need to decide on the value for em/initial_size_MB?

What are your suggestions?

regards.

[Former Member]

Hi,

Go with 8 gb and then see how things works..

Thanks

Rishi Abrol

[Reagan]

Create an instance profile at the OS level by copying the existing profile.

su - p01adm

cp -rp /sapmnt/P01/profile/P01_DVEBMGS01_sapvap01 /sapmnt/P01/profile/P01_DVEBMGS01_sapvap01_test

cdpro

Modify that copied profile with the recommended valued and set the value for em/initial_size_MB to 6 GB.

Run sappfpar against this profile.

sappfpar check pf=/sapmnt/P01/profile/P01_DVEBMGS01_sapvap01_test

Check what the new output it.

You need to correct the errors if there any.

If there are errors in the shared memory for pools then check the advised size under "Shared memory pools"

Modify those parameters and then check again.

If you want to put 8 GB then increase it accordingly but I suggest to increase them gradually.

Regards

RB

[Former Member]

Hi RB,

I'm proceeding by creating a copy of the instance profile.

In fact, the parameter em/initial_size_MB is already 8GB. Given the fact that the "Total, worst case requirement....: 12303.2 MB", is it advisable to set to 12GB right away or I start with 10GB and test?

regards.

[Former Member]

Hi,

Do you still have issue's

Thanks

Rishi Abrol

[Reagan]

First check whether the memory parameters are set according to the recommendations.

724713  - Parameter Settings for Oracle Solaris 10 and above

146289  - Parameter Recommendations for 64-Bit SAP Kernel

I suggest you to check the extended memory parameter (ztta/roll_extension) values of the user context than extending the EM pool size (em/initial_size_MB)

Regards

RB

[Former Member]

Hi Rishi & RB,

The ztta/roll_extension is set to 8GB currently.

The note 146289  - Parameter Recommendations for 64-Bit SAP Kernel is advising increasing the em/initial_size_mb to a larger value but not too large else it involves lot of overhead. Same for the parameter ztta/roll_extension.

Any suggestions?

regards

[Reagan]

The ztta/roll_extension is set to 8GB currently.

This means ONE user can easily consume 8GB of EM before he starts to use Heap. This is not really a defensive strategy. If I were you I would reduce this parameter to 4 GB

The em/initial_size_mb should always be higher than ztta/roll_extension.

Check Tx ST02 and see the buffer hit ratio of all the buffers. If you see anything below 95 % of hit ratio then consider increasing that.

Cheers

RB

[Former Member]

Hi,

Do you still have issues. First thing .

ztta/roll_extension is set to 8GB is too high. I would set it to max 3gb and extended memory to 8gb.

Thanks

Rishi Abrol

[Former Member]

Hi Rishi & RB,

I completely agree that em/initial_size_mb should very much larger than the ztta/roll_extension.

So I'm thinking of reducing the ztta/roll_extension to 4 GB and may be set the em/initial_size_mb to 12 GB.

I've attached a screenshot of my ST02, I think I definitely need to change the values for the buffer parameters with too many swaps.

Please check and give your suggestions.

regards.

[Reagan]

Increase the Table definition, Initial Records. Export/Import, Exp/Imp buffers by 30%

Regards

RB

[Former Member]

Hi,

Mate tell me one thing how much memory do you thing that the OS will take as with 12+4 there is no more room for Os memory.

Try to keep the extended memory to 8 gb

Another thing if keep it 12gb there can be changes that you can have system stand still due to no memory.

Thanks

Rishi Abrol

[Former Member]

Hi Rishi & RB,

The 12+4 means 12 for SAP and 4 for the OS. In fact, I'll increase the physical memory to 16GB. (The database is already in a separate box).

I have a test system with same configurations, I'll do it there first and see.

On the buffer side, I have the parameters (with huge swaps) as follows:

Export/import buffer EIBUF

rsdb/obj/buffersize        40000 kB    Size of export/import buffer

rsdb/obj/max_objects       20000       Max. number of objects in the buffer

rsdb/obj/large_object_size 8192  Bytes Estimation for the size of the largest object

rsdb/obj/mutex_n           0           Number of mutexes in Export/Import buffer

Program buffer PXA

abap/buffersize 600000 kB   Size of program buffer

abap/pxa        shared      Program buffer mode

Should I increase all of these by a certain amount?

regards.

[Reagan]

The fact is that there some custom z-reports and z-transactions that take up quite some memory and the system becomes very slow for users, especially during peak periods.

How did these programs perform on the test environment ?

I would first get the custom programs optimized to run on the production system.

The modifying the parameters of the SAP systems should be the last option.

First check whether the present parameters are set according to the recommendations.

Check this SAP note

724713  - Parameter Settings for Oracle Solaris 10 and above

Run sappfpar and check whether the memory allocation is within the present limit.

I suggest you to perform a run time analysis of the custom programs to see where exactly the problem is.

Regards

RB

[Former Member]

Hi Rishi & RB,

The z-reports/z-transactions have been optimised but they are heavy due to the amount of data. I too think of changing the memory parameters as a last option.

I've already configured /etc/project as per note 724713.

I've attached the sappfpar check, please see and give your comments whether improvement is required.

regards.

sappfpar.txt.zip

[Former Member]

Hi,

I think as the shared pool size 10 should be 124000000.

Have you changed other parameters Suggested earlier.

Thanks

Rishi Abrol

[Reagan]

 Key:   10  Pool
            Size configured.....:   128000000 ( 122.1 MB)
            Size min. estimated.:   119836380 ( 114.3 MB)
            Advised Size........:   124000000 ( 118.3 MB)

It is just a warning and not an error.

The shared memory pool 10 is a bit over the advised size and that barely makes an impact.

Total, minimum requirement.......: 10395.9 MB
Process local heaps, worst case..: 1907.3 MB
Total, worst case requirement....: 12303.2 MB

The ABAP needs 12303.2 MB of memory. So make sure the box is configured with sufficient memory for the SAP, Database and for the OS.

Also take SMD into consideration if there is one running.

Regards

RB

[Former Member]

Hi Suraj,

Which OS is this running on?  If Windows, then check out the note for Zero Memory management.

Regards,

Graham

[Former Member]

Thnx Atul & Graham,

OS is Solaris 10.

SAP Release is EHP6 FOR SAP ERP 6.0 (SAP_APPL on release 606 level 4).

I had already gone thru some of the related links you mentioned. Is it enough to increase the parameter em/initial_size_MB? What is the relation of this value as compared to the physical memory? Also, I suppose we need to consider other parameters like ztta/roll_extension & abap/heaplimit....

regards,

[Former Member]

Hi,

First of all i would suggest you to keep the memory parameters same across the Central and the dialog instance same as it helps you to avoid issue.(There is no such limitation given by sap why i am saying that if you have certain jobs run by any user and is run on the application server and it fails some time as the there is not much memory and runs fine on the central one )

Another thing i want to ask you why do you want to increase it as it give us more details .

Thanks

Rishi Abrol

[Former Member]

Hi Rishi,

The fact is that there some custom z-reports and z-transactions that take up quite some memory and the system becomes very slow for users, especially during peak periods.

Additional physical memory is available and so I want to increase the memory in view of improving the performance.

Also, I want to increase the memory of the Central Instance and the Dialog instance as well, any keeping the memory parameters the same for these 2.

regards.

[Former Member]

Hi,

Yes you should increase em/initial_size_MB as the first part and then .

Pm is physical memory

[RAM] = size of the physical main memory

[PM] = value of the profile parameter PHYS_MEMSIZE (standard value=[RAM])

[US] = maximum possible number of users (calculated from [PM]) -

Standard values for zero administration memory management

|Profile parameter      |Standard 32-bit|Standard 64-bit|Unit      |

|------------------------|---------------|------------------------|

|    em/initial_size_MB  |----    [PM]  |----    [PM]   |Mbyte     |

|---    em/max_size_MB  |---    20000  |---   100000   |Mbyte     |

|  em/address_space_MB  |-----    512  |-----   4096   |Mbyte     |

|----  ztta/roll_first  |-------    1  |-------    1   |Byte      |

|---    ztta/roll_area  |---  2000000  |---  3000000   |Byte      |

|  ztta/roll_extension  |  2000000000  |  2000000000   |Byte      |

|    abap/heap_area_dia  |  2000000000  |           2000000000   |Byte      |

| abap/heap_area_nondia  |  2000000000  |           0  |Byte      |

|  abap/heap_area_total  |  2000000000  |[PM]*1048576   |Byte      |

|-    rdisp/ROLL_MAXFS  |  [US] * 100   |  [US] * 100  |8KB-Block|

|---    rdisp/ROLL_SHM  |  [US] * 100   |  [US] * 100  |8KB-Block|

|---    rdisp/PG_MAXFS  |---    32768  |---    32768   |8KB Block |

|-----    rdisp/PG_SHM  |   [US] * 50  |   [US] * 50  |8KB-Block|

This is as a part of Note 88416 - Zero administration memory management for the ABAP server

So if the value is more in your system just adjust related to this.

Dont forget to check the parameters using sappfpar at os level.

Thanks

Rishi Abrol

[AtulKumarJain]

Hi Suraj,

Please check

http://scn.sap.com/thread/1788609

http://help.sap.com/saphelp_nw2004s/helpdata/en/02/9626e7538111d1891b0000e8322f96/content.htm

Please provide your os type and sap relase info

BR

atul