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Allocating Datacom data sets using DSNTYPE=LARGE


Article ID: 15857


Updated On:


Datacom DATACOM - AD Datacom/AD


Does Datacom support allocating large format sequential data sets greater than 65,535 tracks with DSNTYPE=LARGE?


Datacom/AD 14.0 and higher


Datacom supports the use of large format sequential data sets which can be larger than 65,535 tracks  (4369 cylinders) per volume. 

Allocate a large format data set by using the DSNTYPE=LARGE parameter on the DD statement in the JCL. 

However, extended format data sets defined with DSNTYPE=EXT, DSNTYPE=EXTREQ or DSNTYPE=EXTPREF  are not supported because they cannot be accessed using the EXCP access method which is used by Datacom.