CDSR keyword of the DFSMShsm startup procedure

When you specify CDSR=YES and CDSQ=NO, DFSMShsm serializes the control data sets with a shared ENQ/RESERVE. This means that all DFSMShsm hosts in your HSMplex must have HOSTMODE=MAIN and must implement the same serialization technique.

When the serialization technique has not been specified, the default serialization technique depends on the value of HOSTMODE:

If HOSTMODE=MAIN, DFSMShsm assumes CDSR=YES.
If HOSTMODE=AUX, DFSMShsm indicates an error with message ARC0006I.

When using CDSR=YES, if two or more DFSMShsm hosts are started simultaneously, small windows exist where lockouts can occur. You may want to consider using CDSQ instead.