IBM z/OS manual Unix System Services benefits can include, Distributed Computing Services

•More fi le descriptors per UNIX process are provided in z/OS 1.6, which supports up to 64K per process.

•Additional support for 64-bit programming, conditional variables in shared memory, Euro symbol, and superkill support, along with enhancements to the automount daemon and Unicode.

UNIX System Services benefits can include:

•Development and execution of UNIX applications — z/OS is a UNIX platform

•Increased application portfolio on z/OS as Independent Software Vendors can use USS to port their applications to z/OS

•Portability of applications to and from other platforms

•Use of UNIX development skills in a z/OS environment

•Consolidate multiple UNIX systems

•Scalability for high growth UNIX applications

•Parallel Sysplex support to share UNIX fi le systems benefi ts with Web server applications and others who access the hierarchical fi le system. This support can make your data and information that reside in the HFS available to your customers at any time, no matter where the applications are running in the Parallel Sysplex envi- ronment.

Distributed Computing Services

z/OS Version 1 Release 6 base elements and components

Network File System (NFS)

DCE Base Services

Distributed File Service (including zFS and SMB)

z/OS UNIX supports hierarchical fi le systems that use UNIX APIs. Applications can work with data in both UNIX hierar- chical fi le systems and traditional zSeries data sets.

zSeries File System (zFS)

zFile System (zFS) is the strategic UNIX fi le system for z/OS and complements the z/OS Hierarchical File System (HFS). zFS uses the same APIs as HFS.

zFS can provide the following benefi ts over HFS:

•Improved performance

•Additional function

–Disk space can be shared between fi le systems in the same data set

–File system quota (maximum fi le system size). With zFS the fi le system quota can be increased with a simple administrative command

–Can improve failure recovery. zFS performs asynchro- nous writes to disk and does not wait for a synch inter- val to begin writes.

zFS or zFS-related administration, system management, performance, confi guration support, and scalability have been further enhanced in z/OS 1.4:

•Dynamic reconfi guration for fi le system confi guration options.

•Dynamic use of secondary allocation for a zFS aggre- gate (data set) or fi le system.

•Improvements in the UNIX System Services automount support for zFS.

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