Feisty Fawn upgrade failure : Microsoft-like behavior

[Jonathan D. Graham]

Attempting to upgrade from ubuntu 6.10 to 7.04 and I get the following error in a popup:

Not enough free disk space

The upgrade aborts now. Please free at least 489M of disk space on /usr. Empty your trash and remove temporary packages of former installations using 'sudo apt-get clean'.

But, this is completely wrong as df /usr reveals:

/dev/sda5              4032092   2982116    845152  78% /

So, 845M of disk space...almost twice the required space.

So, has Ubuntu gone the way of Microsoft or is there some command line thing I
can do to override disk space checks and force the upgrade to proceed?

Thanks,
Jonathan Graham
jgraham at Ucar.edu