max_async_ports

max_async_ports specifies the system-wide maximum number of ports to the asynchronous disk I/O driver that processes can have open at any given time.

Acceptable Values:

Minimum
1
Maximum
Default
50

Specify integer value. For more information, see Specifying Parameter Values.

Description

max_async_ports limits the total number of open ports to the ansynchronous disk-I/O driver that processes on the system can have at any given time (this has nothing to do with any RS-232 asynchronous data-communications interfaces). The system allocates an array of port structures for each port when it is opened that is used for all communication between the process and the asynchronous disk driver. The number of asynchronous ports required by a given application is usually specified in the documentation for that application (such as database applications software, video management software, etc.).

To determine a suitable value for max_async_ports:

  1. Determine how many ports are required for each application and/or process that uses asynchronous disk I/O.

  2. Determine which of these applications will be running simultaneously as separate processes. Also determine whether multiple copies of an application will be running at the same time as separate processes.

  3. Based on these numbers, determine the maximum number of open ports to the asynchronous disk driver that will be needed by all processes any given time to obtain a reasonable total.

  4. Set max_async_ports to a value that is not less than this number.

    Additional Information