IBM manual 3.2 OS/390 User Catalogs, LOADxx Prompt Nucleus Device Suffix Feature

IPL unit_address LOADPARM where LOADPARM bytes contain:

bytes 1--4 5--6 7 8

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿ IODF DASD ￿ LOADxx ￿PROMPT FEAT. ￿ ALT NUCx ￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

IODF	LOADxx	prompt	nucleus
device	suffix	feature	suffix
number

See Managing Catalogs, SC26-4914, chapter 2. You must ensure that all OS/390 data sets required for IPL are cataloged in all catalogs that might be used as an alternate master catalog. Other than content, there is no difference between a user catalog and the master catalog. A catalog is the OS/390 master catalog by virtue of the fact that it was designated as such during IPL.

The master catalog must be on a volume that is mounted and available at all times. The master catalog should be password protected or secured via RACF. This is to insure that user data sets are not cataloged in the master catalog and to insure that end users cannot uncatalog critical system data sets.

Formerly, a single catalog could not serve as the master catalog for more than one system at a time. However, a master catalog could be accessed from another system as a user catalog.

You can now share a master catalog between multiple systems. See Managing Catalogs, SC26-4914, chapter 2.

With the introduction of MVS/SP 5.1.0, an installation that has multiple MVS images can share a master catalog and share an IPL volume among multiple MVS images. The system data sets, SYS1.LOGREC and SYS1.STGINDEX are no longer fixed named and unable to be shared. They can now be shared and specified by the installation. In addition, a system symbolic, &SYSNAME, was introduced and can be used as part of data set name specifications for some parameters in PARMLIB. When you use &SYSNAME, data set name specification becomes flexible and you do not need a separate parameter specification for each system in the sysplex.

For example, we can specify the following LOGREC=SYS1.LOGREC.&SYSNAME. The symbolic name, &SYSNAME can also be used in other PARMLIB parameter specifications. You can use &SYSNAME for IEASYSxx parameters VIODSN=, PAGE=, SWAP=, DUPLEX=, and NONVIO=. You can use &SYSNAME for SMFPRMxx parameters DSNAME= and SID=. Catalog if it has been connected to the second system¢s master catalog via the AMS ²IMPORT CONNECT² command.

5.6.3.2 OS/390 User Catalogs

User catalogs contain data set information for user data sets. They should be created as ICF catalogs. VSAM user catalogs may be accessed during the migration period, but should only be used if VSE access is required. They should be converted to ICF catalogs once the migration is over.

Chapter 5. Disk and Tape Storage Considerations 115