msgseg

msgseg specifies the system-wide maximum total number of message segments that can exist in all message queues at any given time.

Acceptable Values:

Minimum
1
Maximum
32767
Default
2048

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

Description

msgseg, multiplied by msgssz, defines the total amount of shared-memory message space that can exist for all message queues, system-wide (not including message header space).

The related parameter, msgssz (message segment size in bytes), defines the number of bytes that are reserved for each message segment in a queue. When a message is placed in the queue, the length of the message determines how many msgssz segments are used for that message. Space consumed by each message in the queue is always an integer multiple of msgssz.

msgseg (message segments) defines the number of these units that are available for all queues, system-wide.

Queue Size and Fragmentation

Total space available for messages in a queue is defined by the product of msgseg * msgssz. Changing the ratio of these two values changes how message space is fragmented for any given messaging usage pattern.

Additional Information