There are provided a method of transforming a non-transformed stored logical data object (LO) device into a transformed LO and system thereof. The method includes: a) in response to a respective transformation request, logically dividing the non-transformed LO in a first segment and one or more non-transformed subsequent segments, the segments having predefined size; b) generating a header for the respective transformed LO; c) processing the first segment; d) overwriting the first segment by said generated header and the transformed first segment; e) indexing the first transformed segment and the one or more non-transformed subsequent segments as constituting a part of the transformed LO; f) generating at least one index section; and g) updating the indication in the header to point that the non-transformed LO has been transformed in the transformed LO including the generated header, the first transformed segment, the one or more subsequent segments including data in non-transformed form and the at least one index section.