Dataset and HFS File System Access

z/OS has both MVS datasets, and Hierarchical File System (HFS) files. As both types must be accessed by the SFTP server, there must be a mechanism for distinguishing between them. Traditionally, MVS datasets in z/OS are accessed using the filename format //'NAME.OF.MVS.DATASET', while HFS files are accessed using the filename format /path/to/hfs/file.

In z/OS, if a dataset name is not enclosed in single quotes, the user prefix is added in front of the dataset name. For example, if user USER1 has a dataset DATASET.NAME1, the user can access it using the dataset name //DATASET.NAME1. It is also possible to use an absolute prefixed name //'USER1.DATASET.NAME1'.

z/OS has also library datasets, whose members are accessed using the dataset name //DATASET.NAME1(MEMBER1).

System symbols can be used in dataset names and volume serial numbers. The symbols are resolved on the host where the dataset resides.

Case-Sensitivity of HFS and MVS Names

HFS file names are case-sensitive. For example, /tmp/MYFILE and /tmp/myfile result in two different files.

MVS dataset names are case-insensitive. For example //'USER1.DATASET.NAME1' and //'user1.dataset.name1' are handled the same way.