Provided are a method, system and program for maintaining and using
information on updates to a data group after a logical copy is made of
the data group. A first logical copy of a data group in a storage at a
first point-in-time is established. The first logical copy maintains data
to reconstruct the data group as of the first point-in time after the
data group has been updated following the first-point-in time. Indication
is made of regions of the data group updated at the storage after
establishing the first logical copy. A second logical copy of the data
group in the storage at a second point-in-time is established. The second
logical copy maintains data to reconstruct the data group as of the
second point-in time after the data group has been updated following the
second point-in time. The indicated regions of the data group updated
between the first and second points-in-time are saved in a change list.