Operating System and Hardware Requirements (UNIX)

Memory Consumption

Below is an estimated calculation of memory consumption in an SAP instance:

Memory Type

Size

64-bit executables and data segment for 60 work processes

 1 GB

Program and table buffers

 1.5 GB

Other shared memories

 0.5 GB

Extended memory

 4 GB

Heap requirement for large batch jobs

 2 GB

Total

 9 GB

This means that you have to reckon with up to 9 GB of virtual address space for each SAP instance, and possibly with the database and all other external programs in addition.

To ensure that the maximum virtual address space requirements - also for worst case scenarios - can be met by the relevant physical background memory, approximately 20 GB of hard disk space is required for the swap area (see below).

Prerequisites

The following requirements must be met so that you can use memory management with your SAP System:

·        The swap space may not fall below a specified level.

·        You may have to install additional main memory.

·        Various operating system parameters must be set correctly.

For more information about prerequisites for swap space see Swap Space Requirements and Determining Swap Space Requirements (UNIX).

The following documentation contains more detailed information on changing kernel parameters and the software requirements for various UNIX systems:

·        UNIX Systems: SAP Software on UNIX -- OS Dependencies. You receive this document with the installation and upgrade packages.

The following documentation contains details on hardware requirements:

·        For installations: you can find details in the installation documentation.

·        For upgrades: you can find details in this document and the upgrade documentation. For additional information, see the upgrade and installation notes in SAPNet.

You can find more information under:

Data Segment Size (UNIX)

VPAGEMAX under OSF/1

Checking the Hardware and Operating System of the Host System