Modifies the system's idea of the number of physical pages of memory after the OS and firmware are accounted for.
Unsigned long
Number of usable pages of physical memory available on the system—not counting the memory where the core kernel and data are stored.
1 to amount of physical memory on system
Pages
No
None
Whenever you want to test the effect of running with less physical memory. Note that because this parameter does not take into account the memory used by the core kernel and data as well as various other data structures allocated early in the startup process, the value of physmem should be less than the actual number of pages that represent the smaller amount of memory.
Unstable