z/OS: XMS Access Method

Prerequisites for Using XMS under z/OS

Task List

Verify that software requirements are met.
Verify that the SAS SVC routine has been installed.
Define resources for the XMS access method.
If using network security, set the appropriate SAS system options
Set the SAS/SHARE SUBSYSID= option, if applicable.

Software Requirements

Ensure that the following requirements are met:

Base SAS and either SAS/CONNECT or SAS/SHARE are installed on both the client and the server.
XMS has been installed on both the client and the server.

Installation of the SAS SVC Routine

The SAS SVC control program routine is an interface between the z/OS operating environment and a specific request, such as "third-party checking." This facility provides verification in the form of calls for authentication of user IDs and passwords and of library authority.

Install the SAS SVC routine, if necessary.

If you have already installed the SAS SVC routine for SAS 9.2 of SAS software, do not repeat the step here. If you need to perform the installation, see the Configuration Guide for SAS 9.2 Foundation for z/OS for details.

Because SAS SVC in SAS 9.2 is backward compatible, it replaces the SAS SVC routines from previous releases. You can continue using previous releases of Base SAS, SAS/CONNECT, and SAS/SHARE with the SAS 9.2 SAS SVC that is installed on your system.
Verify the SVC routine SAS system options.

Verify that the SAS system options for the SVC routine accurately reflect the way that the SAS SVC is installed. The SAS system option SVC0SVC should be set to the number at which the SAS SVC is installed (for example, 251 or 109). If the SAS SVC is installed at 109 as an ESR SVC, the SAS system option SVC0R15 should be set to the ESR code (for example, 4).
Verify installation on all systems, as needed.

If you have more than one z/OS system, verify that the SAS SVC is installed on all the systems that will be running SAS/CONNECT or SAS/SHARE at your site.

Defining Resources for the XMS Communications Access Method

Network Administrator: Before you can use SAS/CONNECT and SAS/SHARE with the XMS communications access method, you must first define XMS resources for the z/OS operating environment. For the tasks to define resources for SAS/CONNECT and SAS/SHARE, see System Configuration for the XMS Access Method.

SAS/CONNECT and SAS/SHARE Network Security

Encryption is the process of transforming plaintext into a less readable form (called ciphertext) by using a mathematical process. The ciphertext is translated back to plaintext for anyone who can supply the appropriate key, which is necessary for decrypting (or unlocking) the ciphertext.

For complete details about using network security, see the SAS/CONNECT User's Guide. After network security is set up in your environment, you set a SAS encryption option that is appropriate to the network security service and to the requirements of the client or the server session.

SAS/SHARE SUBSYSID= Option

SUBSYSID=anchor-point

stands for subsystem identifier, which specifies the cross-memory anchor point that identifies the inactive z/OS subsystem. The subsystem is defined by your network administrator during the XMS access method configuration. For details, see System Configuration for the XMS Access Method.

Defining an inactive subsystem causes a z/OS computer to create a subsystem communications vector table (SSCVT) at IPL time. The SSCVT chain is in common memory and is easily accessible to the XMS access method routines. The SSCTSUSE field of the SSCVT is available to these routines and is used as the anchor point for their control blocks.

The default value for SUBSYSID= is SAS0. You must set this option to enable clients to access the server with the XMS communications access method. Set this option at both the SAS/SHARE server and at each client that will access the server.

Top of Page