Considerations for native ASCII environment support

For applications running on z/OS V1R2 (and higher), a native ASCII environment is provided for z/OS UNIX file processing.

In this environment, applications can operate on files in either EBCDIC or ASCII format as well as other data formats defined with a coded character set identifier (CCSID) without translation, provided the data is already defined and stored in the data format wanted.

For the z/OS NFS server to operate properly on z/OS UNIX files in this environment, consider the following important factors:

Unicode Services must be installed and set up on the system to let the NFS server use it for text translation. With the NFS version 4 protocol, z/OS NFS conversion of UTF-8 text data and metadata requires setting up a conversion environment using the z/OS Unicode Services by creating a Unicode conversion image that defines conversion tables with UTF-8 [CCSID 1208].
Two processing attributes, cln_ccsid and srv_ccsid, are available for the NFS server for translation purposes as well as for the creation of new files. The srv_ccsid attribute determines the CCSID of newly created z/OS UNIX files. If srv_ccsid is not specified as an installation default or at mount time, then new files continue to be created as untagged, or with a tag of 0x0000 and the old translation method of using translation tables specified by the xlat keyword applies.
Processing (read/write) of tagged files depends on the different server options specified.