Note 133909 - Maximum value for PG_MAXFS, PG_SHM, ROLL_MAXFS, ROLL_SHM

Summary
Symptom
Transactions terminate with messages such as:
SYSTEM_NO_MORE_PAGING, EXTRACT_NO_MORE_PAGING, MEMORY_NO_MORE_PAGING

Transactions terminate and refer to problems in the roll memory such as:
<ROLL-FL> get block: no more free blocks
<ROLL-FL> put block: BlockId %ld too high (%ld)

Other terms
PAGFIL<Inst.No>.DAT (Windows) or PAGFIL<Inst.No> (Unix and Linux)
ROLL, roll file, roll buffer
Reason and Prerequisites
Due to special applications, especially when you use
the ABAP EXTRACT language constructs excessively, an overflow
of the SAP paging file occurs.
However, since "normal" internal tables are no longer stored
in the paging area as of Release 3.0B, this problem only affects special applications in which the predefined size of the page file is not large enough.
Solution

Use the following profile parameter to increase the size of the paging area of the application server:

rdisp/PG_MAXFS = <size>

Here, <size> stands for the size of the paging area in blocks of 8 KB. Up to a value of 250,000, you must simply make sure that there is sufficient space for the paging file in the data directory of the application server. If the value is 250,000, the size of the paging file can be up to 2GB.

(See also Note 0097497 for the recommended global setting)

If the parameter value is greater than 250,000, you must take into account other restrictions, which are explained below:

On 32-bit platforms, the size of the paging file is limited to 2 GB.
A part of the paging area can be buffered in the shared memory, but the buffering is severely limited by the address space restriction on 32-bit platforms. The size of the buffered portion in the paging is determined by parameter rdisp/PG_SHM = <size>. Its value is also specified in 8 KB blocks.
Therefore, the following applies to the maximum value of rdisp/PG_MAXFS:
rdisp/PG_MAXFS must be less than 250,000 + rdisp/PG_SHM

On 64-bit platforms, the size of the paging file is not limited to 2GB, provided that the file system allows files larger than 2 GB. The value of parameter rdisp/PG_MAXFS can be larger than 250,000 on 64-bit platforms.

In profile maintenance, a maximum value of 250,000 is set. If you use a value greater than 250,000, the system issues a warning message, but you can ignore it provided you adhere to the restrictions mentioned above.

The information about paging also applies to the roll file and roll buffer. The relevant parameters are rdisp/ROLL_MAXFS and rdisp/ROLL_SHM.

For all releases with a kernel patch version up until May 2006 approximately, the size of the roll buffer and paging buffer is limited to 2 GB. If the block size is 8 KB, the values of parameter rdisp/PG_SHM and parameter rdirp/ROLL_SHM cannot exceed 250,000.

As of approximately May 2006, a patch that lifts the roll buffer and paging buffer restriction is provided for kernel releases as of kernel release 640. The patch is contained in the CST Patch Collection 17 2006.

The roll buffer and the paging buffer are located in shared memory segments 8 and 9. The size of these shared memories must be sufficiently large. Possible size restrictions may be imposed by the operating system, or due to the fact that these are contained in a shared memory pool. The size of shared memory pools is limited to 2 GB.
Header Data


Release Status:Released for Customer
Released on:22.07.2010  09:04:19
Master Language:German
Priority:Recommendations/additional info
Category:Customizing
Primary Component:BC-CST-MM Memory Management
Affected Releases
Release-Independent
Related Notes


 
1081722 - SAP Paging in shared memory
 
182201 - SAPFGVTR: EXTRACT_NO_MORE_PAGING (-> account modification)

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