Dynamic socket limits In z/OS V1R12, z/OS UNIX System Services supports changing the number of reserved ports for Common Inet, the maximum number of sockets that can be obtained for a given file system type, by using the SET OMVS and SETOMVS operator commands. This can help you improve availability by making it unnecessary to restart OMVS to change these values UNIX System Services (USS) support for RFC 5014 USS and Communications Server support for Source Address Selection/Get Partner Info has USS updates for the new socket options for Default Address Selection as described in RFC 5014. There are macro updates for the new socket options and common INET support for these options when there are multiple TCPIP stacks configured. Support for mmap for NFS client z/OS UNIX System Services supports the memory mapping (mmap) function for files in zFS and HFS file systems. In z/OS V1R12, new support allows applications to use memory mapping for NFS client files. This will enable NFS-mounted file systems to be used by applications that use memory mapping. 1.4 zFS support The z/OS Distributed File Service zSeries File System (zFS) is a z/OS UNIX System Services (z/OS UNIX) file system that can be used in addition to the hierarchical file system (HFS). zFS file systems contain files and directories that can be accessed with z/OS UNIX application programming interfaces (APIs). These file systems can support access control lists (ACLs). zFS file systems can be mounted into the z/OS UNIX hierarchy along with other local (or