Does CA Datacom version 12.0 support the full capacity of a 3390 Mod 54 device?

Document ID : KB000018755
Last Modified Date : 14/02/2018
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Description:

We are in the process of moving from 3390 Mod 9 and Mod 27 devices to Mod 54 devices, and want to be sure that CA Datacom running version 12.0 and 14.0 will support this.

Solution:

BACKGROUND

Here are a few statistics on the Model 9, 27 and 54 devices:

ModelTracks/VolumeCylinders/VolumeBytes/Volume
9150,25510,0178.51 GB
27491,40032,76027.84 GB
54982,80065,52055.68 GB

Beyond the Mod54 is the ModA, which is an EAV (Extended Address Volume) device, with a capacity above 65520 cylinders. These devices can, in theory, be configured to have a maximum of 268,434,453 cylinders (in z/OS 1.11, it was limited to 262,668 cylinders, and in 1.13 the limit is 1,182,006 cylinders or 1TB). Files on these volumes can be created using Extended Formatting, however, CA Datacom does not support the Extended Format file type, as it actually changes the physical representation of the data on the device from the Basic format files.

In terms of CA Datacom support for EAV devices, we have published an Informational Solution -

RI42648 (DB 12.0 #86), "*PDC: STATEMENT ON CA DATACOM SUPPORT FOR EAV DASD"

that addresses this. Here is an excerpt of that document that pertains to version 14.0 and 12.0:

CA Datacom R&D wants to document its current support for IBM's Extended Address Volume (EAV) disk technology.

For purposes of this document, a "CA Datacom dataset" includes the following:

  • The Datacom Control File (CXX)
  • The Datacom Log File (LXX) and Force Area (FXX)
  • All Datacom data areas
  • All Datacom index areas

CURRENT EXPLOITATION SUPPORT:
*Version 14.0*
Version 14.0 supports the CA Datacom datasets mentioned above as 'included' on all cylinders of EAV DASD, to the extent allowed by IBM. All future releases will do so as well.

CURRENT TOLERATION SUPPORT:
*Version 12.0*

Currently Version 12.0 provides toleration support for EAV disks. Any CA Datacom dataset can be allocated on EAV DASD devices below the 65,521 cylinder line. Any attempt to open a CA Datacom dataset mentioned above as 'included' with a cylinder number greater than 65,520 will be rejected by the z/OS Operating System.

Consequently, since a Mod54 device includes up to the 65520 cylinder mark, both version 12.0 and 14.0 will support these devices without a problem. As with any change, you will want to thoroughly test your processing on the new devices before introducing it to your production systems.

As always, please contact CA Technologies support for CA Datacom if you have further questions.