Why does FASTCOPY load a new PDS/E in multiple extents.

Document ID : KB000020074
Last Modified Date : 14/02/2018
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When FASTCOPY loads a new PDSE, it is allocated in multiple extents, unless the file is a NON-SMS file without RLSE coded. This issue even occurs with CONTIG coded.

The same allocation parameters when used with IBM's IEBCOPY creates a PDSE in a single extent.


FastCopy processing may cause a new PDSE to use multiple extents under the following conditions:

  1. PDSMAN FastCopy is active
  2. The output PDSE DD is specified within a step invoking IEBCOPY and

    1. Specifies DISP=NEW

  3. Specifies space release, by using either

    1. A MGMTCLAS defined with IMMED or COND release

  4. A SPACE= parameter with ,RLSE.

Before the COPY (or MOVE) operation, FastCopy does an OPEN for Output followed by a CLOSE to force the VTOC to be updated with DCB information.

This CLOSE causes space to be released before the COPY operation which means the new PDSE may start with a small primary allocation and require secondary extents.

There are a couple of circumventions:

  1. Allocate the NEW PDSE in a previous step which does not do an OPEN (for example, using IEFBR14).
    Then, use a refer back to allocate the PDSE in the IEBCOPY step.
    The PDSE will no longer be a new library and the space release performed during CLOSE does not occur.

  2. Do not specify RLSE or a Management Class with Release during Closedefined.