FASTCPK Introduction

Fast, Efficient and Minimally Disruptive z/OS DASD Volume Reorganization

Modern disk arrays are still regarded by the z/OS operating system as a set of conventional DASD Volumes. Each logical volume in the array has a fixed number of cylinders, and space is managed in the usual way – with a standard VTOC and VTOCIX.

As described in more detail in the Case for FASTCPK White Paper or in the Technical section, the issues of fragmented freespace, multi-extent datasets, over-allocated datasets and wasted space are as important today as they have always been.

Introducing FASTCPK

FASTCPK is a DASD Volume reorganization tool that provides a fast, efficient and minimally disruptive solution to a wide range of DASD related Storage Management issues, including:
  • Free Space Fragmentation. FASTCPK can “defrag” or consolidate free space on a volume into as few as one or two contiguous areas, reducing the fragmentation index (fragindex).

  • Multiple Extents. FASTCPK merges the extents of Sequential, PDS, PDSE, VSAM, DB2 and Extended Format VSAM data sets.

  • Wasted Space. FASTCPK releases all or part of the unused space within Sequential, PDS, PDSE, VSAM, DB2 and Extended Format VSAM data sets.

  • VTOC errors. FASTCPK analyzes a VTOC and detects logical errors (e.g. invalid F5's and incorrect free space definitions).
See the Technical section for an example FASTCPK job that will do all of the above, across a specified range of DASD volumes.


FASTCPK is ultra-fast!
  • Get the job done in just a few minutes with a minimum of intrusion.

  • Typically, it takes LESS than 1 minute to consolidate free space, merge extents and release unused free space on a 3390-9.

  • The SIZEKEEP parameter can limit the amount of data moved by FASTCPK, allowing it to finish even faster.

  • You can opt to just release unused free space using the optional TYPE=RLSE mode of FASTCPK, which usually runs in less than 10 seconds!

Simulation & Reporting

FASTCPK can produce a wide range of information, in both detailed and summary format.
  • The MAP function allows you to map out the contents of selected volumes.

  • The SIMULATE feature lets you see the effects of a Compaktion without actually having to run it for real.

Before and After maps can be produced for each volume processed, either on a SIMULATE or a real Compaktion, together with a concise summary of the effects of the Compaktion.

Here is an example of the summary report:

Key Benefits
  • Re-gain control over the utilization of your z/OS DASD space and ease dataset allocations by reducing the over-allocation of data sets.

  • Reduce the occurrences of x37 abends and limit the number of multi-volume data sets.

  • Detect VTOC errors before they can do any harm to your data.

  • In a single execution, FASTCPK can reduce free space fragmentation, merge the extents of multi-extent datasets and release unused free space.

Related Product: FDRREORG (VSAM and IAM Reorganization)

If you want to logically re-organise your VSAM (or IAM) files, see the FDRREORG section for more details.

Related Product: FDRARC (Data Migration & Space Management for z/OS)

If you want to save DASD space by migrating unwanted datasets to a lesser expensive medium, see the FDRARC section for more details.

For more introductory information on FASTCPK, see the Product Portfolio Sheet

For more technical detail on FASTCPK, see the Tech Detail section.

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