New in RTD/zOS V8.1

New Features in RTD/zOS V8.1 


RTD/zOS is the new name for the basic RTD version (previously RTD/RIO).

The following features and improvements are incorporated in RTD/zOS version 8.1

  • The EXCP I/O processing has been improved by allowing either 5, 10 or 15 tracks to be processed by a single channel program, rather than the previous 1-5 tracks.
  • The RELEASE function will now not reduce an empty SMS extended format compressed dataset to less than the required minimum size for compression.
  • The volume level SET statement "ERASE" option "ERASE=NEVER" has been added to suppress unnecessary RACF calls if erasing of freed extents is never used.
  • RTD/zOS internal program code has been extensively modified with the aim of providing greater reliability and maintainability, and reducing CPU usage in the RTD/zOS STC processing.
  • The RTDISPF dialog has been improved as follows:
    The user may now select configuration members (global, volume and dataset) by selecting from a list of members for the main panel ‘GF’ and ‘CF’ options. The user may supply generic masks in the Dialog Options panel in order to limit the members shown in the select list.
    A similar option has been added to the filtered LOG display function (main panel ‘LF’ option). The log filter PARMLIB member name in the Dialog Options panel may now be a generic mask or omitted, allowing the member to be selected when the ‘LF’ option is invoked.
    The RTDISPF dialog statistics function now supports a screen size of up to 62 lines of 160 characters (as supported by ISPF).

RTD/zOS Version 8.1 and RTD/DB2 Version1.1 and later versions require at least the following System z hardware features

  • Long-Displacement Facility
  • Extended-Immediate Facility
  • General-Instructions-Extension Facility
  • Execute-Extensions Facility.

Retired Functions

  • Support for SNAPHOT devices has been removed from the product.




Rapid Incremental Optimizer


The following features and improvements are incorporated in RTD/RIO version 8.0

  • Previously (since Version 7.0) RTD has supported its three functions (RELEASE, COMBINE, DEFRAG) for the track managed area of an EAV volume (basically a model 54 volume). With version 8.0, this support is now extended to the cylinder managed area of EAV volumes.
  • RTD/RIO now provides the EAVAREA parameter of the volume level SET statement. The options TMA, CMA or BOTH specify whether the track managed area (TMA), cylinder managed area (CMA) or both (BOTH) should be processed if the SET statement is selected. In addition the CMAPOLICY parameter can be used to determine the “aggressiveness” of DEFRAG processing in the CMA area.
  • New algorithms for the candidate extent selection and free space selection have been developed for CMA processing. In addition, the new candidate selection can also optionally be used for TMA processing. This is expected to give improved and more flexible DEFRAG performance in many cases. The option is invoked by specifying the new TMAPOLICY parameter on the volume level SET statement or by specifying neither TMAPOLICY nor DEFRAGPOLICY, in which case TMAPOLICY=1 is assumed by default. The old mechanism is still available and can be invoked by specifying DEFRAGPOLICY=5 or 6 without the TMAPOLICY parameter.
  • The RELEASE function will now skip processing for an empty SMS extended format compressed dataset.
  • The global function statements SET statement has been extended with the GSI=n parameter. This specifies the general scheduling interval to be used if the CONFIG=Z (null configuration) option is also specified (for real configurations the general scheduling interval is specified as part of the configuration, and the GSI parameter is ignored). Up until now the scheduling interval of the previously active configuration continued to be used.
  • The channel programs for performing ERASE of free extents have been improved, reducing the length of channel programs and time for execution.
  • The device type in statistics is now qualified with the model/type, such as 3390-3.
  • Volume count of volumes processed in last cycle has been added to messages RTDD19I and RTDD25I. The MAXDATA percentage (if applicable) is now issued via a new message RTDD26I.
  • RTD/RIO no longer displays the differences in fragmentation index obtained via the z/OS LSPACE macro. Instead it displays the reduction in number of free extents on the volume.




  • A new global level function has been provided to dynamically set the current RTD/XFR configuration at different times of day and/or on different days of the week. In addition a new "null configuration" ("Z") is provided to completely stop RTD/XFR processing.  This functionality can significantly reduce the need for RTD/XFR control via external applications or operator commands. To aid correct functioning of this new feature, the RTD/XFR general scheduling interval is now synchronized to the hour. That is, a new interval always starts just after a new hour, regardless of when the previous interval started.
  • RTD/XFR now issues TRANSWAP at start of volume processing in DAS for MAS mode rather than DONTSWAP. In addition, the Control Address Space (CAS) in MAS mode is no longer non-swappable during volume processing.
  • The RELEASE function has been improved to
    Allow PDS Compress without track release with the RELEASE=CPR dataset level SET statement option.
    Suppress free extent release for RELEASE=PART (thus applying PERCENTFREE or PERCENTUSED to the entire allocated space) with the ALLEXTS=YES dataset level SET statement option. (Previously RELEASE=PART would always free any completely empty secondary extents).
    With the ALLEXTS=YES option SET statement specified also allow truncation of empty secondary extents for RELEASE=PART with the TRUNCSEC=YES (default NO) dataset level SET statement option.
    With the RLSPHASE=CPR/RLS dataset level Include/Exclude statement parameter the statement may be applied to the selection for the COMPRESS option or the subsequent selection for the actual RELEASE processing.
    The PDS Compress function will no longer be invoked for a RELEASE=MC request with COMPRESS=YES if no release is performed due to the SMS settings.
  • A new option NOGDGBASEENQ=YES/NO on the dataset level SET statement enables suppression of ENQ serialization for the GDG base when processing a GDS dataset or extent.
  • A new option ERASE=ALWAYS on the volume level SET statement is provided at the volume level to support OEM DASD Dynamic Provisioning solutions by always erasing freed extents without reference to RACF or VSAM Catalogue settings.
  • Major changes have been made to internal storage management and message passing to significantly reduce CSA usage and provide other technical advantages by means of shared 64 bit storage. In addition volume control information is now held in non-CSA shared storage to avoid copying this data between address spaces in MAS mode.
  • CPU usage during UCB scanning has been reduced via new hash table logic.





  • EXCP code has been rewritten to use improved channel programs reducing the amount of page fixing below 16M and in the 31 Bit user area.
  • Improved diagnostic information (ABEND messages and Dump Data) after a system abend. Diagnostic information is also written earlier in the abend handling process to provide more accurate data for later diagnosis.
  • By use of the NO1DAY=YES option on the dataset level SET statement RELEASE processing can be performed on datasets with no last referenced date which are less than one day old.
  • At start-up, the licensed options (MAS, FRO, PM) are listed with message RTDM10I, as well as any unlicensed options (as previously).
  • Message RTDM03W (license will expire soon) now shows the number of days until expiration.  


Extended Fast Replication Support

Fast Replication Option includes support for RVA/Snapshot devices (since RTD/VAO V3) and FlashCopy Version 2 (since RTD/XP V6). These powerful functions become ever more important as data capacity on modern EAV devices limits the ability to perform efficient I/O processing with EXCP.

This latest version of  RTD, now called RTD/XFR (for "Extended Fast Replication") extends these previous capabilities by removing restrictions on processing large numbers of extents with FlashCopy, and supporting modern DASD in Remote Pair PPRC configurations.

To allow effective control of such processing, the volume level selection criteria have been expanded with three options:

  • The FROCAP (FRO capability)  option may be used to select volumes allowing Snapshot (SS) FlashCopy (FC) or FlashCopy with Remote Pair capability (RP) processing.
  • The VSIZE option may be used to select particular DASD volume sizes (S, M, L, VL and EAV, corresponding to DASD 3390 models 3, 9, 27, 54 and EAV).
  • The APRIM (Active Primary) option may be used to select volumes which are currently configured as PPRC primary volumes.

In addition, the following existing volume level processing options have been extended:

  • The FRO option ‘REQ' indicates that FRO processing is required. If it cannot be performed then no COMBINE or DEFRAG processing will be performed. If an FRO dataset operation fails, the operation will not be completed with EXCP (the previous default).
  • The PPRC option ‘PM' indicates that Preserve Mirror (required) processing is to be performed for a PPRC primary volume. If this is not possible, no processing will be performed on the volume.


Additional New Features in RTD/XFR V7.1

  • Defrag candidate (extent group) selection has been optimised to prevent continual moving of extents at each processing interval in certain pathological cases and to treat extent groups broken by very small free areas as a single group.
  • The Message Level parameter on the RTD ISPF Dialog Configuration Control Specifications panel now allows the value ‘3'. With this level, messages are written to the RTD Log dataset showing the type of processing performed for each data movement operation.
  • Detailed messages indicating the z/OS and DFSMS levels are written to the console (and RTD Log) at start-up to aid in diagnosis in the case of problems.
  • The number of error messages issued (code E) is shown in a console message and the RTD Log when a new Log Archive dataset is written or RTD/XFR is closed down.
  • The Function Starting message RTDV21I now contains the SMS storage group (if present) as well as the volume name.
  • Diagnostic routines for abend messages and system dumps have been improved (for the rare cases where this can be important).



Support for Extended Address Volumes (EAV)

RTD/XP now supports Release, Combine and Defrag processing for datasets allocated on EAV volumes. Currently, processing is limited to the track managed portion of such volumes. This support is only available under z/OS Version 1.10 (or higher).

Additional Dataset Selection Criteria

The following new selection criteria are now available at the dataset level:

  • The EAV option may be used to select datasets allocated on EAV volumes with format 8/9 DSCBs (whether or not cylinder managed extents are present).
  • The CYM option may be used to select datasets allocated on EAV volumes with cylinder managed extents. Note that RTD/XP does not (currently) process such datasets.


Support for Large Datasets and Large Extents

RTD/XP now supports Release, Combine and Defrag processing for Large Datasets (DSNTYPE=LARGE). RTD/XP will now allow data movement for large extents (greater that 32K Tracks) if the dataset is on an FRO (Flashcopy 2 or Snapshot capable) device.

This support is only available under z/OS Version 1.7 (or higher).


Detection of Interrupted Processing

RTD/XP V7 will scan the RTD Log Dataset on start-up to determine if processing for one or more volumes was not complete (due to unexpected termination of RTD/XP or z/OS, for example). A list of such volumes will be written to the z/OS console and the RTD log.

Datasets Catalogued in Master Catalogue

Up to now (non-VSAM) datasets catalogued in the master catalogue would be bypassed for all RTD/XP processing. A new SET Statement option (IGNORE=MCAT) allows specific (non-VSAM) datasets to be processed even if catalogued in the master catalogue.

RTD Optional Utilities (ROU)

RTD Optional Utilities is a suite of programs (currently 2) to obtain added value from the results of RealTime Defrag processing.

The current programs allow the copying of RTD Log and Statistics datasets to sequential datasets for subsequent processing (analysis, download to PCs for processing with tools such as Excel, etc.)

Statistics data may be written in fixed field or CSV (comma-separated values) format. Log data is formatted as in the RTD ISPF Dialog Log display function.

The programs allow flexible selection of records via filter functions and ordering of records in forward or reverse date/time order.

Please see the ROU Manual for further details.