History of Disk Image Computing

I have a slightly off-topic question:

Did the "virtual disk" feature of IBM's PC Support software, in 1993, for the AS/400, System 36, and System 38 systems use any sort of sector allocation information, as in disk imaging and disk cloning?

I am asking here because I cannot find any other expert who knows the answer. In generally, I need to learn about the history of disk imaging software, to learn whether or not these IBM products did that. I am pretty sure that the answer is no, but I want to confirm that.

You can read about the virtual disk feature of the PC Support software in this U.S. patent:

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PAL…

I am wondering whether the virtual disk feature discussed there stored any sector-allocation information as in Acronis products.

Thanks!