In a Parallel Sysplex®, you need only one lock structure for VSAM RLS because only one VSAM sharing group is permitted.

Recommendation: For high-availability environments, use a nonvolatile coupling facility for the lock structure.

If you maintain the lock structure in a volatile coupling facility, a power outage could cause a failure and loss of information in the coupling-facility lock structure. Should that happen, all outstanding recovery (CICS® restart and backout) for any affected data sets must be completed before new sharing work is allowed for those data sets.

The name of the coupling-facility lock structure is IGWLOCK00.

Related reading: For more information about the IGWLOCK00 lock structure, see z/OS DFSMSdfp Storage Administration.