When you specify CDSQ=YES, DFSMShsm serializes the control data sets (between multiple DFSMShsm hosts) with a global (SYSTEMS) exclusive enqueue while allowing multiple tasks within a single DFSMShsm host environment to access the control data sets concurrently. This optional CDS serialization technique is implemented with a SCOPE=SYSTEMS resource that enables GRS or a similar product to enqueue globally on the resource as an alternative to reserving hardware volumes. All hosts in an HSMplex must implement the same serialization technique and must propagate the QNAME of ARCENQG as shown in Table 2. Do not specify CDSQ=YES in the DFSMShsm startup procedure unless you have a cross-system serialization product propagating the ARCENQG resource.

To use the AUX mode of DFSMShsm, you must specify CDSQ=YES or CDSSHR=RLS in each startup procedure. If the HSMplex consists of an AUX mode host and more than one z/OS image then you must use GRS, or a similar product to propagate enqueues.