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Background documentationMemory Management on Linux Locate this document in the navigation structure

 

For SAP on Linux two variants of memory management are available.

The required variant can be activated in the SAP instance profile parameter es/implementation.

  • MAP implementation (es/implementation=map)

    This variant is mainly used on 32 bit systems, and is described in detail in SAP Note 386605. As of SAP kernel 6.20 an SAP system on Linux uses the MAP implementation by default. Here, only the currently active user context is mapped to the address space of the work process.

  • Standard implementation (es/implementation=std)

    With this variant memory management of an SAP system on Linux is the same as on classical UNIX systems. Here, all user contexts in the system are mapped to the adress space, which means that this variant is suitable only for 64 bit systems.

    For more information, see SAP note 941735.

While only the MAP implementation should be used on 32 bit Linux, both variants can be used on 64 bit systems. Since there is no 32 bit restrictions, on 64 bit Linux systems there is no longer any need for the special MAP implementation. For this reason, as of SAP Kernel 7.10 the STD implementation for SAP systems on 6 bit Linux is activated by default.