Extended memory and blocksize parameters

[former_member273662]

Dear All,

Our current configuration is

SAP ECC 5.0 Release 6.40 Level 16

Oracle 10.2.0.2.0

HP/UX 11iv1

48 GB memory

Our extended memory setting is

em/initial_size_MB = 8000

em/blocksize_KB = 1024

Disclaiming parameters not set

es/disclaim_threshold_MB

es/blockdisclaimsize_KB

I have read Note 835474 and I would like to increase the extended memory to

em/initial_size_MB = 12000

em/blocksize_KB = 4096

Calculated from st02 and st04, my total SAP and Oracle memory usage is 24.5 GB.

Are there any risks involved? Should I need to set the disclaiming parameters as well? If yes, what are the good starting points?

Thank you,

Hon

[TomCenens · Accepted solution]

Hello Hon

em/initial_size_MB = 12000

em/blocksize_KB = 4096

These would not be a problem as long as you have sufficient extended memory on your HP/UX server which should be the case if this is the only SAP system running on it.

"Calculated from st02 and st04, my total SAP and Oracle memory usage is 24.5 GB."

You can use sappfpar to check the Abap 'worst case' consumption.

Setting the em/initial_size_MB higher only makes sense if the value is actually reached by your users daily use. Which you can easily get from ST02 if the maximum is reached (historical information also available).

If the SAP system has a Java stack it is very important that the memory consumed by the J2EE engine fits in the extended memory (so you should have < 100% memory use on your HP/UX server).

There is no real need to start setting those disclaimer parameters in your case.

I don't see any "risk" in setting those parameters when taking into account above information.

Kind regards

Tom

[former_member273662 · Accepted solution]

Hi Tom,

Thank you. My concern was mostly with the effect of the blocksize_KB change from 1024 to 4096. I would expect this change will improve performance as well. I am testing the changes in our test system now. Thanks again.

Best regards,

Hon

[TomCenens · Accepted solution]

Hello Hon

The effect of the blocksize_KB change from 1024 to 4096 is that when memory is allocated, a bigger part is allocated, which has advantages and disadvantages. The advantage is better performance, the disadvantage is that more memory is consumed as the block size is larger but since you have enough extended memory it won't be a problem.

Kind regards

Tom