DFHSMDATASETSERIALIZATION and USERDATASETSERIALIZATION: Specifying data set serialization

Explanation: DFHSMDATASETSERIALIZATION | USERDATASETSERIALIZATION are mutually exclusive, optional parameters that apply to volume migration and volume backup in a multiple-DFSMShsm-host environment. These parameters specify whether data set serialization of system resources is provided for all data sets by system facilities.

DFHSMDATASETSERIALIZATION specifies that data set serialization of system resources during volume migration and volume backup in a multiple-image environment is not provided by system facilities, and that DFSMShsm should implement its requirements for resource serialization.

USERDATASETSERIALIZATION specifies that data set serialization of system resources during volume migration and volume backup in a multiple-DFSMShsm-host environment is provided by system facilities. Examples of such system facilities are Global Resource Serialization and JES3 data set reservation. In a single DFSMShsm host, data set enqueue is provided. DFSMShsm should optimize its requirements for resource serialization with those facilities.

Note:

The setting of this parameter affects the value of the DFSMShsm integrity age. Refer to the Integrity age for space management for more information on the relationship between integrity age and DFHSMDATASETSERIALIZATION | USERDATASETSERIALIZATION.
In DFSMShsm Version 1 Release 5, the incremental backup function was restructured in order to improve the performance of that function. This improvement is only effective when USERDATASETSERIALIZATION is specified. Only use the SETSYS DFHSMDATASETSERIALIZATION command if it is required by your environment. Otherwise, it is recommended that you use the SETSYS USERDATASETSERIALIZATION command.
The fast subsequent migration function supports reconnection only in a USERDATASETSERIALIZATION environment.
Some data sets, such as multivolume physical sequential data sets, are processed only with SETSYS USERDATASETSERIALIZATION.

Attention

In a multiple-DFSMShsm-host environment, do not specify USERDATASETSERIALIZATION unless you have a data set serialization facility installed and enabled on your system. Otherwise, serious data-integrity problems can occur.

SMS relationship: Parameter differs in meaning when applied to SMS-managed or non-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 DFHSMDATASETSERIALIZATION.