A storage apparatus enables efficient data restoration even if restoration
is attempted using several different restoration points. The storage
system is connected to a host apparatus, and includes a storage unit
having various logical volumes formed therein and a controller configured
to control I/O processing with respect to the storage unit. The
controller stores journal data for a data volume in a journal volume, and
also stores snapshot data for the data volume in a snapshot volume. In
accordance with a restoration request designating a restore point, the
controller restores the data volume to the state it was in as of the
designated restore point, by applying the snapshot data stored in the
snapshot volume and subsequently applying the journal data stored in the
journal volume. During that process, the controller saves the data in the
data volume to which certain journal data is going to be applied, in a
journal backup volume.