CONVERSION and NOCONVERSION: Specifying whether reblocking is to occur

Explanation: CONVERSION | NOCONVERSION are mutually exclusive, optional parameters specifying whether DFSMShsm reblocks eligible data sets during recall or recovery. This parameter is not applicable to system-reblockable data sets, whether they are SMS or non-SMS.

CONVERSION specifies that DFSMShsm can reblock the data sets during recall or recovery.

REBLOCKTOANY is an optional subparameter of the CONVERSION parameter specifying the type of reblocking during recall or recovery of data sets that use DFSMShsm as the data mover and also specifies reblocking to any DASD device type supported by DFSMShsm.

NOCONVERSION specifies that DFSMShsm cannot reblock the data sets even if you specified the data set reblock exit.

SMS relationship: Parameter applies in some instances to SMS-managed DASD volumes or data sets.

SETSYS default: None.

DFSMShsm default: If you do not specify either parameter on any SETSYS command, the DFSMShsm default is NOCONVERSION.

Note:

DFSMShsm reblocks only nonkeyed, physical sequential data sets with the following record organizations: fixed-blocked, fixed-blocked-standard, variable-blocked, or variable-blocked-spanned. If a data set specified LRECL=X, DFSMShsm does not support reblocking.
DFSMSdss reblocks only physical sequential and partitioned data sets with the following record organizations: fixed-blocked, fixed-block-standard, and variable-blocked.
You must specify the CONVERSION parameter if you want to use the data set reblock exit (ARCCDEXT). You can prevent DFSMShsm from reblocking user-selected data sets by using the data set reblock exit.