SAP with Microsoft SQL Server 2005: Best Practices for High Availability, Maximum Performance, and Scalability42
network packet size
The network packet size option determines the size of packets transmitted over the network. SQL Server 2005 allocates three buffers that use the parameter size for every connection. This parameter does not have an effect if the application request contains a different value. At connection time, SAP NetWeaver Application Server overwrites the network packet size option in SQL Server 2005 when it is set to other than 8192.
Because 8192 is set by the SAP client application, the network buffers are allocated outside of the SQL Server buffer pool, but in the SQL Server virtual address space. SQL Server usually leaves a virtual address space of approximately 300 to 350 megabytes (MB) outside the buffer pool. In large SAP systems, up to 150 MB of the 300 to 350 MB can be allocated by the network buffers. In turn, this can lead to problems with the virtual address space in a 32-bit computing environment.
As a workaround, SQL Server can be forced to leave more virtual address space by adding –gxxx, with xxx=number specifying MB – default =256 MB in SQL Server 2005, as a start up parameter to define a value above 256 MB. This is not a problem in 64-bit computing platforms.
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