Change aptitude upgrade folder

To change the default folder where temporal files are stored when doing an aptitude upgrade just create one folder /apt/partial in some specific place:

 mkdir -p /some/path/apt/partial 

And then modify or create the file /etc/apt/apt.conf and add this line:

 dir::cache::archives "/some/path/apt"; 

source : http://ostico.it/content/linux/aptitude/how-change-default-aptitude-download-directory