[ Thanks to finid
for this link. ]
“The installation program on this edition is similar to the
Ubiquity installation program, which is used on the main edition,
the one based on Ubuntu. But while the Ubiquity installation
program incorporates an automatic disk partitioning phase, the LMDE
lacks it. As a result, installation of LMDE requires that the disk
be partitioned manually . This tutorial offers a step by step on
how to partition a disk for installing LMDE.“Images used in this tutorial were obtained from an installation
in a virtual environment with a disk space of about 100 GB. The
steps would be the same if you are installing on real hardware
with, say, 500 GB of disk space.”