The present invention provides techniques for managing storage based
replication. Specific embodiments provide techniques for performing
system backup and restoring. In specific embodiments, benefits such as
keeping a remote mirror between a primary volume and a secondary volume
in operation can be provided. Since the remote mirror is usually used for
disaster recovery purposes, where the mirrors must be always in-sync
state, being able to take a backup without breaking the remote mirror can
help provide a constant duplicate copy of production information in case
of emergency, for example. Further, in some embodiments, a user can take
backups of more than one generation by setting up two or more secondary
volumes (SVOLs) for one primary volume (PVOL).