To add to other replies to Bob's query (from my notes):

RESTORE STGpool vs. RESTORE Volume      The Restore Stgpool and Restore Volume
                                        commands are very closely related.
                                        Under the covers, most of the code is
                                        the same.  The major differences are:
                                         - Restore Stgpool restores primary
                                           files that have previously been
                                           marked as damaged because of a
                                           detected data-integrity error.  This
                                           is done regardless of whether the
                                           volume has been designated as
                                           destroyed.
                                         - Restore Volume allows you to specify
                                           the volume name(s) rather than using
                                           Update Volume to designate the
                                           destroyed volume(s).
                                        For restoring a small number of volumes,
                                        the Restore Volume is more convenient,
                                        particularly if you are not interested
                                        in restoring damaged files on other
                                        volumes.  For restoring damaged files
                                        or a large number of destroyed volumes,
                                        Restore Stgpool is preferable.