Explanation of semaphore, message queue and shared memory settings in /etc/system

Details:
This TechNote gives a brief explanation about the shared memory, message queue and semaphore settings used in /etc/system.

Shared memory
set shmsys:shminfo_shmmin = minimum shared memory segment size
set shmsys:shminfo_shmmax = maximum shared memory segment size
set shmsys:shminfo_shmseg = maximum attached shared memory segments per process
set shmsys:shminfo_shmmni = number of shared memory identifiers


Message queues
set msgsys:msginfo_msgmap = number of entries in message map
set msgsys:msginfo_msgmax = maximum message size
set msgsys:msginfo_msgmnb = maximum number of bytes on queue
set msgsys:msginfo_msgmni = number of message queue identifiers
set msgsys:msginfo_msgssz = message segment size (multiple of word size)
set msgsys:msginfo_msgtql = number of system message headers
set msgsys:msginfo_msgseg = number of message segments


Semaphores
set semsys:seminfo_semmap = number of entries in semaphore map
set semsys:seminfo_semmni = number of semaphore identifiers
set semsys:seminfo_semmns = number of semaphores in system
set semsys:seminfo_semmnu = number of undo structures in system
set semsys:seminfo_semmsl = maximum number of semaphores per id
set semsys:seminfo_semopm = maximum number of operations per semop call
set semsys:seminfo_semume = maximum number of undo entries per process

More information about suggested default values can be found in TechNote 238063, which can be found in the Related Section of this TechNote. Sun Microsystems SunSolve document ID 2270 available at http://sunsolve.sun.com also provides more detail about each of these kernel tuning parameters.