The ICF Catalog structure
z/OS ICF Catalogs
The ICF (Integrated Catalog Facility) Catalog setup is one of the strengths of the z/OS operating system. To find a file, you do not need to know anything about directory structures or paths, in fact both those terms are meaningless under z/OS. All you need to know is the file name. A big advantage of this is that there is no need to change JCL. or batch scripts if you move a file to a different volume. Usually every file can be located by its name, and all files have unique names. z/OS file names, or rather dataset names, consist of a number of 1-8 character qualifiers, separated by periods. So a typical file might be called 'sysinf.job.library' The 'sysinf' part of the name is called the high level qualifier, and is an important part of the cataloging process
The ICF Catalogs page describes how an ICF catalog works
The Catalog structure is complicated and can go wrong. The Fault finding page describes typical catalog problems, how to find them and how to fix them.
The ultimate catalog fix is to recover it, but to do that you need good backup. The Backup and Recovery page describes this.
While ICF catalogs are a strength, they are also a weakness as if they fail then data cannot be accessed. The final section on Catalog Products details lots of products to help manage catalogs, both IBM and third party.
Alternatively, use the left hand frame to navigate between pages.