4.3. Sharing VSAM data sets
In this section we discuss the sharing of VSAM data sets from one address space throughout a Parallel Sysplex® and what that it implies, such as level of data integrity, MVS enqueues, VSAM mechanisms to protect data integrity, and SHAREOPTIONS.
To protect the integrity of your VSAM data sets, VSAM uses internal locks and issues ENQs in SYSVSAM major name, which invokes the MVS Enqueue Manager routine to serialize the resource locally. To serialize the full cluster across systems, it is required to have the Global Resource Serialization (GRS) or an equivalent product with the caution of not placing SYSVSAM resource name in RNL exclusion list.
Some of the consequences of placing SYSVSAM in the exclusion list include: ...