Hierarchical file system (HFS) in Mainframe UNIX (2 of 2)

Hierarchical File System is a UNIX compliant file system that runs under z/OS UNIX System Services. HFS has been functionally stabilized and will eventually be dropped from support. zFS is IBM’S preferred file system for Unix System Services files.
HFS file have DSTYPE=HFS and can be allocated using the IEFBR14 utility

//S1 EXEC  PGM=IEFBR14
//SYSPRINT DD SYSOUT=*
//DDNAME1  DD DSN=AX540.TEST1.HFS,
//            DISP=(NEW,CATLG),
//            SPACE=(1,(50,50,1)),AVGREC=K,
//            DSNTYPE=HFS
//*

The file information is a bit confusing as it looks like a cross between a PDS and a PDSE, but the difference is that the DSNTYPE is HFS as specified above.

HFS data sets contain a UNIX tree structure that makes sense to OMVS utilities, but not to Z/OS utilities in general. For example HFS files cannot be copied with IEBCOPY. You need to OMVS COPYTREE utility to copy an HFS file. From TSO option 6, enter the following command : n.b. this is a foreground copy so it will lock your session out until it completes.

Copytree /source/directory/path  target/directory/path

  • Before you can use a new HFS it has to be mounted.

To do this –

  • Use the command TSO ISHELL to get into OMVS
    Set up the DIRECTORY structure for your new file system.
    Select ‘FILE Systems’ from the top line menu and select the ‘Mount’ option.
    Update the following fields

MOUNT POINT (UNIX path)
FILE SYSTEM NAME (zOS dataset name)
FILE SYSTEM TYPE – HFS

Hit ‘Enter’ and your new file system should be mounted. You can use the MOUNT TABLE option from the FILESYSTEMS menu to check.

Ref:lascon

Author: Srini

Experienced software developer. Skills in Development, Coding, Testing and Debugging. Good Data analytic skills (Data Warehousing and BI). Also skills in Mainframe.