SAP Buffer - ST02

[Former Member]

Dear SAP Guru,

Following is my understanding about the SAP buffer which I want to confirm whether it is correct.

Below points are based on the scenario of

Physical RAM -16 GB

Virtual Memory (Swap Space)u2013 49 GB (3 times of RAM)

OS u2013 Unix

The virtual memory is set to 3 times of the physical RAM. It may vary depends upon OS.

The SAP buffer is set at the time of installation.

Normally these buffers are set to 60-40 ratio. 40% of physical RAM is allocated to SAP Application and 60% RAM is allocated to DB.

Eg: 10 gb to DB and 6 GB to SAP Application.

Some percentage of RAM is also consumed by OS

From above points, I understand that

SAP buffer will be allocated only in 6 GB memory and it donu2019t take any space from virtual memory in the above mentioned scenario.

I have observed some swappings occurred in sap buffers in ST02.

This means that the allocated 6 GB is not sufficient for the buffers.

I want to confirm, when these buffers are full they will not swap the objects to virtual memory.

Above mentioned are s my understanding about the SAP buffer which I want to confirm whether it is correct.

Regards

[Former Member]

Vijay,

Few swaps a day or once in a while are ok. Please post the details about what is the swap figure, how frequently this happens and buffer name. But in the meantime, take a look at following links.

[http://help.sap.com/saphelp_nw70/helpdata/EN/bc/4a813b680c250fe10000000a114084/content.htm]

[http://help.sap.com/saphelp_nw70/helpdata/EN/02/9625e3538111d1891b0000e8322f96/content.htm]

Hope this helps.

Manoj

[JPReyes]

Can you specify what buffer are you talking about?... if you're talking about the Program buffer?

The size of the buffers are directly link to the value stated on the profile

Regards

Juan