Document Structure

Introduces Volume Shadowing for OpenVMS and describes how it provides high data availability.

Illustrates various shadow set configurations.

Describes how to set up a volume shadowing environment, including information about setting shadowing system parameters, booting a system that uses a system disk in a shadow set, and booting satellite nodes from a shadowed system disk.

Describes how to use DCL commands to create, mount, dismount, and dissolve shadow sets. The chapter also describes how to use the SHOW DEVICES command, the System Dump Analyzer, and the F$GETDVI lexical function to obtain information about shadow sets on a running system.

Describes how to use the OpenVMS system services in a user-written program to create and manage shadow sets. The chapter also describes how to use the $GETDVI system service to obtain information about shadow sets.

Describes how the copy and merge operations maintain data consistency and availability during changes in shadow set membership.

Describes how the minicopy operation can be used, in a carefully controlled environment, to reduce the time required for a member to be returned to a shadow set. Typically, the member is removed for backing up data.

Describes how to use host-based minimerge (HBMM) to shorten the time of a merge operation.

Describes how to perform system management tasks on shadow sets, including performing backup and upgrade operations, performing shadowing operations in OpenVMS Cluster systems, and handling crash dumps on the shadow set.

Includes helpful information and guidelines for achieving better performance from shadow sets.

Lists messages related to volume shadowing that are returned by the Mount utility and the VOLPROC, shadow server, and OPCOM facilities.

Glossary

Lists and defines the shadowing terms used in this manual.