How to determine MAXDS value and size of ROOT LDS?

Products

• Dispatch Output Mgmt

Issue/Introduction

How to determine MAXDS value and size of ROOT LDS?

Environment

CA Dispatch,11.6, 11.7, MAXDS, ROOT, LDS, SIZE

Resolution

CADDSPL LDS File Considerations

* ROOT LDS Considerations:

When initializing the Root LDS, there are two size factors that work together that must be defined correctly:

- The physical size of the Root LDS file

  Each individual LDS file is limited to a 2 GB maximum size, which is about 2900 Cyls on a 3390. See Calculating the Physical Size of the Root LDS in the following section.

- The MAXDS value, or maximum number of reports and MSGCLASS entries that can be stored within the LDS files at any one time. This value will be set by the MAXDS parameter during Root LDS initialization.

Important! The MAXDS parameter cannot be dynamically changed after the LDS files have been allocated and configured. Therefore, use extreme care when calculating this value. Changing this value requires the unloading of your LDS files, reinitializing the Root LDS and Appended LDS files with the new MAXDS value, and reloading the data into the LDS files.

 

* MAXDS Considerations:

- Please refer to the CA Dispatch System Programmers Guide - Chapter 7: CADDSPL Operation section 'CADDSPL LDS File Considerations' specifically "MAXDS Considerations" for IMPORTANT details on what must be considered in order to determine what the MAXDS value should be set at.

 
* Calculating the Physical Size of the Root LDS

After you have determined the MAXDS value, you can use the CADDMXDS utility to determine the number of 3390 cylinders to allocate for the Root LDS file.

Note: The following clist must be executed during both the original install of the ROOT LDS and when an increase to the MAXDS value is ever done.

To execute this utility, enter the following from the TSO ready prompt or ISPF Option 6:

EXEC 'CAI.CADSJCL(CADDMXDS)' 'nnnnnnnn'

- where n is your MAXDS value.

Information similar to the following will be displayed:

MaxDS specified. . . . . . . . . . . : 123568
Size required for your Root LDS. . . : 36MB
or : 52 Cyls
Maximum MAXDS for this Root LDS. . . : 129328

This sample output indicates that when specifying a MAXDS=123568 you must define your Root LDS with 52 cylinders.

Additional Information

CA Dispatch System Programmers Guide - Chapter 7: CADDSPL Operation section 'CADDSPL LDS File Considerations'