DYNALLOC


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   '-DYNALloc-'

DYNALLOC specifies dynamic allocation, instead of enqueue, to serialize the use of data sets. The data sets whose extents are to be relocated are serialized throughout the copy operation. This allows cross-system serialization in a JES3/MVS environment.

Note:

Serialization is of value only when you use the dynamic allocation or the JES3 interface is not disabled.
Run time increases when you use the DYNALLOC keyword to serialize data sets (as opposed to enqueue) because overhead is involved in dynamic allocation and serialization across multiple processors.
If a data set passes INCLUDE/EXCLUDE filtering and is migrated before BY filtering and the DYNALLOC keyword is used, the dynamic allocation causes the data set to be recalled. DFSMSdss waits for the recall processing to complete. If the data set is recalled to a different volume, a message indicates that the VTOC entry was not found.
For an HFS source data set, DFSMSdss ignores DYNALLOC and attempts to get a SYSZDSN enqueue. If the enqueue attempt fails, DFSMSdss attempts to quiesce the HFS data set.
For a physical data set copy operation, the DYNALLOC keyword will be ignored for the source data set when that data set resides on a dump conditioned volume.