The first time you select ISMF, you get the ISMF Primary Option Menu for end users. To get the ISMF Primary Option Menu for storage administrators (which is shown in z/OS DFSMSdfp Storage Administration), select option 0, ISMF PROFILE. Within the ISMF Profile Option Menu, select option 0, USER MODE, and press ENTER. You get the User Mode Entry panel, where you indicate that you want the storage administrator Primary Option Menu for all future ISMF sessions. To do this, select option 2 on the User Mode Entry panel. After changing the user mode, you must exit ISMF and then return to it to view the Primary Option Menu for Storage Administrators.

z/OS DFSMSdfp Storage Administration explains how to prevent end users from gaining access to the storage administrator Primary Option Menu through the ISMF PROFILE option. The reason for restricting access to the Primary Option Menu for Storage Administrators is to prevent unauthorized users from performing storage administrator tasks.