From Oracle FAQ
The tstshm (test shared memory) utility can be used to evaluate the shared memory configuration of a Unix or Linux system. The output may also be useful if you want to relocate the SGA to a different location in memory. This utility can be found in the server's ORACLE_HOME/bin directory.
Tstshm provides the following information:
- The number of segments of shared memory generated and attached to the process
- The location of the shared memory in virtual memory
- The size of shared memory
- The size of the largest single segment
$ tstshm Number of segments gotten by shmget() = 50 Number of segments attached by shmat() = 50 Segments attach at lower addresses Default shared memory address = 0xb6c5f000 Lowest shared memory address = 0xb6c5f000 Highest shared memory address = 0xb6c5f000 Total shared memory range = 2097152 Total shared memory attached = 104857600 Largest single segment size = 2097152 Segment boundaries (SHMLBA) = 4096 (0x1000)