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WebSphere Application Server for z/OS 8.5 does not use memory mapped files for transaction logs by default

Troubleshooting


Problem

In previous releases of WebSphere Application Server, by default, the server used memory mapped files for translation. To disable MMAP functions, administrators were required to take action. In the Version 8.5 release, the default behavior has changed to not use memory mapped files for transaction logs.

Resolving The Problem

If you require that memory mapping be used for transaction logging, set the com.ibm.ws.recoverylog.spi.NoMemoryMappedFiles property to use memory mapping for the transaction log files on z/OS.

With this option set, you will need to set the size of the transaction log files with care. Memory mapped files cannot be expanded, and they consume a significant portion of the virtual address space available in a 31-bit environment.

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Document Information

Modified date:
06 June 2019

UID

swg21592648

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