CDSSHR keyword of the DFSMShsm startup procedure

When you specify CDSSHR=YES, DFSMShsm serializes the control data sets with the type of multiprocessor serialization requested by the CDSQ and CDSR keywords. However, if you specify CDSSHR=RLS, DFSMShsm performs multiprocessor serialization using RLS. Specifying CDSSHR=NO performs no multiple DFSMShsm host environment serialization at all.

Table 1 shows the serialization techniques available with varying combinations of the startup procedure keywords.

Table 1. DFSMShsm Serialization with Startup Procedure Keywords
CDSQ Keyword	CDSR Keyword	CDSSHR Keyword	Serialization
YES	YES	YES	Both CDSQ and CDSR options are used.
YES	NO or not specified	YES	Only the CDSQ option is used.
With any other combination of specifications		YES	Only the CDSR option is used.
--	--	RLS	Uses VSAM RLS
--	--	NO	No multiprocessor serialization. No other processor shared control data sets.

When the CDSQ and CDSR keywords are specified, DFSMShsm monitors each processor’s updates to the control data sets and ensures that the serialization technique of the processor making the current update is identical to the serialization technique of the process that has made the previous update.

Startup procedure keywords describes the keywords for the DFSMShsm startup procedure. Additionally, an example of the DFSMShsm startup procedure can be found in topic Starter set example.

Table 2 shows the resource names for the control data sets when they are protected with GRS.

Table 2. DFSMShsm Resource Names for Control Data Sets
Major (qname) resource name	Minor (rname) resource name	Serialization result
ARCENQG	ARCMCDS	This enqueue allows global resource serialization of the DFSMShsm MCDS.
	ARCBCDS	This enqueue allows global resource serialization of the DFSMShsm BCDS.
	ARCOCDS	This enqueue allows global resource serialization of the DFSMShsm OCDS.
ARCGPA	ARCRJRN	This enqueue allows only one processor to backup the journal.