di-utils-mapdevfs software package provides mapdevfs utility for the debian installer, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install di-utils-mapdevfs
di-utils-mapdevfs is installed in your system.
Make ensure the di-utils-mapdevfs package were installed using the commands given below,
$ sudo dpkg-query -l | grep di-utils-mapdevfs *
You will get with di-utils-mapdevfs package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | debian-installer udeb packages |
| Package | di-utils-mapdevfs |
| Version | 1.92+deb7u1 |
| Description | mapdevfs utility for the debian installer |
| Sub Section | Debian-installer |