z/OS V2.3 is the last release of the operating system to support the DFS/SMB (Distributed File System / Server Message Block) functionality.  IBM announced that NFS (Network File System) is the strategic file sharing protocol for the z/OS platform (in IBM Software Announcement Letter 217-246).  This is especially important when sharing files between z/OS and the Microsoft™ Windows™ environment.

To help clients shift to use NFS technology, IBM conducted a pilot program with close to two dozen customers across various geographies.  This program helped IBM identify and deliver new function in the areas of installation, security, availability, and operations for the z/OS NFS server. We also identified a few fixes for Windows operating system and worked with Microsoft to have these delivered.

Here's a summary of the function delivered by IBM for use with the z/OS NFS server and the Microsoft™ Windows 10 NFS client.  These enhancements enable clients to more easily migrate to use NFS. The PTFs to the following APARs provide various capabilities and should be installed: 

• OA56251 – allows customers to identify their use of DFS/SMB with a new migration health check. This health check will alert a customer if DFS/SMB is active on their system.
• OA56186 – provides a z/OSMF (documentation only) workflow to help customers configure the z/OS NFS server with step-by-step instructions, especially useful for the first-time z/OS NFS user.
• OA56187 – provides the z/OS NFS client utilities of mvslogin, mvslogout, and showattr for the Windows 10 NFS client. mvslogin and mvslogout allow a non-z/OS NFS client to manage SAF authentication to a z/OS host and showattr displays the z/OS NFS server attributes. 
• OA56224 – provides Kerberos support for the z/OS NFS server when using the NFS V3 protocol, the level supported by Windows 10, to control access to NFS network shares. By providing Kerberos-based authentication, customers can enable authentication and end-to-end encryption between z/OS and Windows environments. This support requires the use of Active Directory. Incidentally, the z/OS NFS server already provides Kerberos support for NFS V4. 
• OA57489 – provides support in the z/OS NFS server to allow the file owner to complete read/write operations despite the state of the file mode.
• OA57577, OA58929, OA59613 - enables the starting of multiple z/OS NFS servers in an INET environment in a single LPAR. Customers can use this support to segregate application workloads, for instance assigning DFS/SMB workloads (migrating to use NFS) to their own individual NFS server, while having their existing applications use a different z/OS NFS server. This capability can also be used to provide improved availability of applications using NFS server on z/OS. 
• OA57493 – provides a customizable Windows-specific attribute in the z/OS NFS server, known as Windows prefix, to help identify connections from a Windows NFS client. This support enables the z/OS NFS server to tailor responses for a better experience when accessing z/OS UNIX directories. 
• OA59843 & OA62161 - eliminates extraneous authentication messages (e.g. RACF ICH408I messages) on the console, when Windows NFS clients access the z/OS NFS server through the Windows prefix mountpoint using SAFEXP mode.  
• OA59310 - This enhancement no longer requires Windows NFS clients to unmount and remount the NFS drives after the z/OS NFS server has been restarted. Incidentally, no longer requiring the unmount and remount of drives was a behavior found in the DFS/SMB server. 
• OA58912 – provides the ability for the z/OS NFS server to use Kerberos authentication with unique application-instance DVIPA. This support will help customers preserve data security while enabling easier movement of the z/OS NFS server between LPARs. 
• OA61777 – provides support for the z/OS NFS server to release an ENQ on the MVS data set, when in rare circumstances the Windows NFS client sends an erroneous lookup with the source directory as a file (e.g. MVS sequential data set) instead of a directory (e.g. MVS PDS or PDSE).

In addition, the following Microsoft fixes have been provided to address problems when using the z/OS NFS server with the Windows 10 NFS client: 

• KB4580386 for builds 1903/1909 (aka 19H1/19H2)
• KB4580364 for builds 2004 (aka 20H1/20H2)

Resolves issue with Windows 10 NFS client unable to access NFS shares hosted on Unix server due to UID/GID issues.

• KB4586819 for builds 1903/1909 (aka 19H1/19H2)
• KB4586853 for builds 2004 (aka 20H1/20H2)

Resolves issue when using wildcarding capability on DELETE command (from DOS prompt) resulting in not all of the files being deleted.

• KB5004293 for builds 1903/1909 (aka 19H1/19H2)
• KB5004296 for builds 2004 (aka 20H1/20H2)

Resolves issue with rename failures on the Windows 10 NFS client after two different mount scenarios.

Finally, we have updated our publication, the z/OS Network File System Guide and Reference, with:

• a new chapter on commands and examples for use with Windows clients
• a new appendix on setting up the z/OS NFS server with Kerberos authentication     

 
I hope this consolidated source is helpful in your use of migration to use the z/OS NFS server with Windows 10 NFS client.