A system, method and computer readable medium for providing a writable
file system snapshot with ditto address feature is disclosed. In an
embodiment of the present invention, the method includes accessing a
first file system snapshot in a set of file system snapshots. A snapshot
includes data contents comprising at least one shadow inode or at least
one shadow inode and at least one data block corresponding to the shadow
inode. The data contents of the first snapshot are copied and written to
the next oldest file system snapshot. Subsequently, the data contents of
the first snapshot are modified in accordance with modifications to at
least one source file corresponding to the first snapshot. Then, a next
most recent file system snapshot is accessed. The data contents of the
next most recent snapshot are copied and written to the first file system
snapshot.