Page space allocation

There are several page space allocation policies used in AIX.

Deferred Page Space Allocation (DPSA)
Early Page Space Allocation (EPSA)

Deferred page space allocation
The deferred page space allocation policy is the default policy in AIX.
Early page space allocation
If you want to ensure that a process will not be killed due to low paging conditions, this process can preallocate paging space by using the early page space allocation policy.
Paging space and virtual memory
The vmstat command (avm column), ps command (SIZE, SZ), and other utilities report the amount of virtual memory actually accessed because with DPSA, the paging space might not get touched.

Parent topic: Memory performance