by C. C. Barnes, A. Coleman, J. M. Showalter, M. L. Walker
This paper discusses the concepts and facilities of the Shared File System (SFS) support for Virtual Machine/Enterprise Systems Architecture (VM/ESA) Coordinated Resource Recovery (CRR). It includes background information on limitations that lead to SFS support for coordination of file recovery functions. The level of support provided by the Virtual Machine/System Product (VM/SP) Release 6 SFS support is identified and contrasted with the support provided in VM/ESA. The paper contains an overview of the system structure and the rationale for the support and is a discussion from the overall perspective of the total system environment and system processing for resource recovery. After the concepts and structure of VM/ESA SFS support are introduced, the paper discusses the specific technology involved in providing SFS support for Coordinated Resource Recovery. This includes a discussion of specific facilities used by SFS and how SFS deals with certain conditions that can arise. In addition, this paper discusses the Conversational Monitor System (CMS) compatibility considerations that contributed to the design of SFS support for Coordinated Resource Recovery. This includes compatibility with prior releases and compatibility with the CMS file system support for minidisks. Finally, some of the future directions for file system support of resource recovery are identified along with some of the challenges that remain to be solved.