Remote mirror and copy is a storage server feature that constantly
updates a target copy of a volume so that it matches changes that were made
to its associated source volume.
The remote mirror and copy feature is a hardware solution that enables
the mirroring of data from one site (the local site) and its associated volumes
(source volumes) to a second storage unit at another site (the recovery or
remote site) and its volumes (target volumes).
Note: Remote mirror and copy
was referred to as Peer-to-Peer Remote Copy (PPRC) in earlier documentation
for the IBM® TotalStorage® Enterprise
Storage Server®. Currently, the remote mirror and copy feature name is
used generically for all methods of synchronous and asynchronous methods.
In addition, in a remote mirror and copy environment, a site where production
applications run might be referred to as the production site, local site,
or Site A. A site that has mirrored data of your local site might be referred
to as a recovery site, backup site, remote site, or Site B.
Remote mirror and copy differs from FlashCopy® in two essential ways. First,
the source and target volumes can be on the same storage server or on separate
storage servers that are located at some distance from each other. Second,
and more significantly, remote mirror and copy does not capture the state
of the source volume at some point in time, but rather reflects all changes
that were made on the source volume to the target volume.