According to the present invention methods and an infrastructure are provided for performing repetitive data protection and a corresponding restore of data for block oriented
data objects comprising several indexed segments.For implementing the invention, timestamps tk are set by a time k; and only the first data modification of a segment is recorded, after a
timestamp tk has been set, by storing the old data contents of said segment together with the segment index i an said
timestamp tk as
undo-log block in a journal, first, before overwriting said segment with the modified new data. The main idea of the invention is that the
undo-log blocks of the segments are distributed to N journals jn, wherein N>1 and n=0, . . . , N-1, such thata) at time tn+(m·N) (0≦n<N) at most m+1
undo-log blocks corresponding to the same segment are recorded in the journal j0,b) during the time interval [tk+(m·N), t(m+1)·N) no duplicates are recorded in the union of journals j0, . . . jk, (0≦k<N), andc) an undo-log block is written to journal jn+(m·N) (0<n<N) if and only if the corresponding segment was modified in time interval [t(n-1)+(m·N), tn+(m·N)) for the last time before the current modification;wherein m=0, 1, . . . ∞ and wherein the timestamps t(m·N) represent consecutive reset points.Then, only journals j0, . . . , jk are needed for a point in time restore of time rk+(m·N) and all changes that were written after t(m+1)·N located in journal j0. Thus, the present invention allows to reduce the amount of data that needs to be read from the journals in order to recover the
system to a given point in time.