Meaning of ORACLE Kernel Parameters

Shmmax-shared memory segment. It is recommended to set a larger value to reach the maximum SGA.
Shmmin-the smallest shared memory segment.
Shmmni-number of shared memory flags.
Shmseg-Maximum number of memory segments that a process can allocate.
Shmall-maximum allowed memory, larger than SGA.
Semmns-semaphores, which are related to the number of processes in ORACLE.
Semmsl-the maximum number of semaphores in a semaphore.
SGA = (db_block_buffers * block size) + (shared_pool_size + large_pool_size + log_buffers) + 1 MB
ORACLE 8.1.X
SGA = (db_block_buffers * block size) + (shared_pool_size + large_pool_size + java_pool_size + log_buffers) + 1 MB
In theory, SGA accounts for 1/2 of the OS physical memory-1/3. We can adjust it as needed.
Several parameters in the/etc/system file in SUN Solaris are also related to memory allocation.
Default settings for ORACLE Installation: Recommended settings:
Set shmsys: shminfo_shmmax = 4294967295
Set shmsys: shminfo_shmmin = 1
Set shmsys: Sh minfo_shmmni = 100
Set shmsys: shminfo_shmseg = 15
Set semsys: seminfo_semmns = 200
Set semsys: seminfo_semmni = 70
Set ulimit = 3000000
Set semsys: seminfo_semmni = 315
Set semsys: seminfo_semms = 300
Set semsys: seminfo_semmns = 630
Set semsys: seminfo_semopm = 315
Set semsys: seminfo_semvmx= 32767
Set shmsys: shminfo_shmmax = 4294967295
Set shmsys: Sh minfo_shmmni = 315
Set shmsys: shminfo_shmseg = 10
Set shmsys: shminfo_shmmin = 1
Meanings of these parameters
Shmmax-shared memory segment. It is recommended to set a larger value to reach the maximum SGA.
Shmmin-the smallest shared memory segment.
Shmmni-number of shared memory flags.
Shmseg-Maximum number of memory segments that a process can allocate.
Shmall-maximum allowed memory, larger than SGA.
Semmns-semaphores, which are related to the number of processes in ORACLE.
Semmsl-the maximum number of semaphores in a semaphore.