Volume Shadowing for OpenVMS

This document describes Volume Shadowing for OpenVMS, Version 7.1, a System Integrated Product for the VAX and Alpha processor families. It provides high data availability by implementing a RAID Level 1 storage strategy, also known as disk mirroring, which maintains redundant copies of data across a shadow set of one, two, or three compatible disk volumes. Key features include transparent read/write operations across shadow set members, automatic repair of unreadable data for supported disks, and seamless operation within OpenVMS Cluster configurations. The document also details hardware/software requirements, configuration limits (up to 500 disks in multimember sets per cluster), and licensing options, which are available on either a capacity or per-disk basis.