File generations are cataloged just like “normal” files with the CATAL macro or the CREATE-FILE-GROUP command. File processing – in this case: creation of the file – is likewise the same as “normal” file processing. The only difference is the format of the file name, which must contain an absolute or relative generation number. When cataloging or creating file generations, the user must ensure that there are no gaps in the sequence of absolute generation numbers, regardless of whether (s)he uses absolute or relative generation numbers in his/her programs or procedures. The group entry is updated automatically by DMS.
The following attributes can be assigned (and modified) separately for individual file generations of an FGG: STOCLAS, IOPERF, IOUSAGE, DISKWR, S0MIGR, AVAIL, USRINFO, ADMINFO (with macros) and STORAGE-CLASS, PERFORMANCE, USAGE, DISK-WRITE, S0-MIGRATE, AVAILABILITY, USER-INFORMATION, FILE-PREFORMAT, ADM-INFORMATION (with command).