Red Hat: Whitepaper: Changes in RPM 3.0

Red Hat Linux 6.0 is/was built and installed using RPM
version 3.0. While continuing to remain compatible with
pre-existing binary packages, reorganization of the internals in
RPM 3.0 permits more reliable package installation.
addition, more flexible configuration during package builds has
been achieved while preserving the original design goal of
reproducible builds of binary packages from source code….”

“One of the most noticeable new features in RPM 3.0 is disk
space checking. Before installing any packages, RPM now ensures
that the system has enough free space for all of the new packages
which are being installed. If there is not enough free space
available, RPM reports which filesystems need more space, and how