Operating Systems

Sometime during the fourth quarter, IBM will deliver the VSE ESA 2.7.3 refresh. Unfortunately, this refresh won’t contain the “service option,” which includes VSE/ESA 2.6.3. Therefore, you will no longer be able to order VSE/ESA 2.6.x from IBM. 

If you’re on a CPU that isn’t supported by VSE/ESA 2.7.x (see IBM VSE/ESA 2.7.x announcement), and you aren’t already on VSE/ESA 2.6.3, place your order now to ensure you will get a copy. 

VTAPE

IBM introduced with VSE/ESA 2.6 and 2.7 a new function package, VTAPE (Virtual Tape). VTAPE consists of two parts. The first part is a program that runs in a class R partition and traps tape requests from an existing VSE/ESA program and JCL, and then processes those requests against a resident VSAM disk file or a non-resident, off-platform file. The second part is the PC application that supports the file access on the PC.

 VSE/ESA Resident Files

For those VSE/ESA customers who don’t have a disk/tape manager that supports disk/tape file independence, this facility delivers that function in the base VSE/ESA package.

 Off-Platform Files

One facility worth noting is the VTAPE-to-PC interface. The ability to read/write to and from offplatform files from a VSE/ESA batch program without any VSE/ESA program or JCL changes certainly has merit in today’s multi-centric platform environment. The offplatform application runs on Windows and various flavors of Unix.

 Installation

You can install the VTAPE-to-PC interface, using these steps:

  1. Install or upgrade to VSE/ESA 2.6 or 2.7. Be sure to obtain the latest PTFs for VTAPE for the release level installed, as they contain the latest required maintenance. You can download the latest copy of the VTAPE client from the VSE/ESA Website and install it on the client(s).
  2. ICCF library 59 contains two members, SKVTAPE and SKVTASTJ. Copy these to your user library for use and modification.
  3. You can use SKVTAPE for creating a VSE/ESA VSAM file for use as a virtual tape. If you don’t intend to write virtual tape files on VSE/ESA disk, there’s no need to copy or use this file. However, if you plan to use VSAM VTAPE files, define the VSAM ESDS and supply the VSE/ESA label JCL.
  4. SKVTASTJ creates the VSE/ESA startup job as TAPESRVR. Z in IJSYSRS.SYSLIB, catalogs LDVTA.PROC, which loads TAPESRVR into the POWER Queue, and executes LDVTA.PROC.
  5. For ease of use, use the program in Figure 1 to create VSE/ESA JCL to issue the VTAPE Start and Stop commands as required. VTAPE Start and Stop commands will start and stop the VSE/ESA server in class R partitions. If you’re using VTAPE to access off-platform data, then a TCP/IP stack must be up, the network must be available, and the VTAPE client must be started on the platform.
  6. Run the VSE/ESA batch program that reads/writes tapes. If you’re accessing the VSAM VTAPE file, simply issue the VTAPE Start/Stop commands.

 

Documentation

The documentation for the client is accessible after installation as a menu item. Also, a readme file is included in the downloaded source. The VSE/ESA documentation is on the VSE/ESA CD-ROM and in ICCF library 59 in the SKVTA*** members. 

Conclusion

VSE/ESA 2.6.x customers who don’t have VSE/ESA 2.6.3, be sure to order it now. VTAPE is a relatively new feature that offers disk device independence and is easy to implement. Thanks for reading the column and good luck with VTAPE.