em/initial_size_MB: Extended Memory Pool Size

Use

This value specifies the Extended Memory pool size that the R/3 System manages for the Extended Memory.

Goal:

Ideally, this pool is large enough to contain the sum of all the user contexts. The pool must always be larger than the size of the parameter ztta/roll_extension. This parameter specifies how much Extended Memory can be allocated to a user context.

If the pool is used up, heap memory is allocated (see Private Memory and Allocating Memory for User Contexts). The work process switches to the PRIV mode and is reserved exclusively for the current user context. After processing the user context, the work process may be restarted automatically, if the process size specified in abap/heaplimit was exceeded.

Basic rules: Ensure that the pool is 10 to 15 times as larger as ztta/roll_extension; The exact value is oriented according to the available swap space and the number of users in the host system.

Integration

The swap space must be sized so that it can contain the R/3 Extended Memory and has enough space for the R/3 usage of heap memory (see Swap Space Requirements). There must also be enough space available for competing system users outside of the R/3 System. The swap space must also be large enough to ensure a safety reserve.

Activities

Unit: 1 MB

Default value: 128 MB

Recommended value: 200 to 500 MB, approximately 5 MB for each R/3 user (pay attention to operating system dependencies)

You can find the values from the configuration examples (Contents button). You can find more information on Windows NT under Setting Dimensions for Sufficient Extended Memory.

Changes: Customers can make changes.