Paging

When a process causes a page fault because of missing data, this data is "paged in". When a process is forfeiting memory the data is "paged out" to swap, subsequently when this data is needed again it is "paged in" again. Paging is different from swapping because swapping moves the entire memory of a process to/from swap. Paging is performed in units of that are of pagesize bytes. Different architectures have different sizes of pages.

Architectures	Pagesize (bytes)
i386	4096
amd64	4096
sparc	4096 or 8192
sparc64	8192
vax	4096
alpha	8192
macppc	4096
mac68k	4096

To find the pagesize of your system try typing "pagesize".

$ pagesize 
4096

Here is sample output from a Solaris 8 production system that is experiencing mild paging, but zero swapping:

 [root@soemhost /tmp]# vmstat -S 60
  procs     memory            page            disk          faults      cpu
  r b w   swap  free  si  so pi po fr de sr m1 m1 m1 m2   in   sy   cs us sy id
  0 0 0 1591144 1483816 0  0 574 2  2  0  0  0  0  0  1  843 1729  457  6 13 82
  0 0 0 1164512 1051184 0  0 42  6  6  0  0  0  0  0  0  729 2268  222  3 30 66
  0 0 0 1253864 1060440 0  0 17  3  3  0  0  2  2  2  1  500 1977  217  6 33 60
  0 0 0 1208336 1058672 0  0 50  8  8  0  0  1  1  1  0  681 2947  252  5 35 60