Figure 2: Operating system strategies

Operating System           Strategy
---------------------      ----------------------------
Sun (pre-Solaris 2.0)      Normal /etc/passwd file (default)
Adjunct Password File

Generic System V.4         Shadow Password File
Sun (Solaris 2.x)          If Shadow file is not present, then default
Sequent PTX                back to the Normal /etc/passwd file.
Pyramid
Data General
Some System V.3

HP/UX                      Normal /etc/passwd file
SGI
Sequent Dynix
DEC Ultrix
OSF/1

AIX                        Security Password File

SCO 3.2.2                  TCB Security
SCO 3.2.4                  TCB Security and Shadow Password File