This chapter describes the minicopy feature of Volume Shadowing
for OpenVMS introduced in OpenVMS Version 7.3. Minicopy and its
enabling technology, write bitmaps, are fully implemented on OpenVMS
Alpha systems. OpenVMS VAX nodes can write to shadow sets that use
this feature but they can neither create master write bitmaps nor
manage them with DCL commands. In a mixed-architecture OpenVMS Cluster system,
only one Alpha system is required in order to use minicopy.
The primary purpose of minicopy is to shorten the time it
takes to return a shadow set member to the shadow set. The shadow
set member is typically removed for the purpose of backing up the
data and is then returned to membership in the shadow set.