>I had about 2.2GB
> free space in root partition which includes /usr and /var when I tried
> upgrade.
>Why did it complain insufficient space? I thought the possibilities are:
>1) Temporary files; but shouldn't 2.2.GB be enough.
It doesn't use temporary files all that much.
>2) The upgrade saves some of the older versions of packages;
> I suppose it doesn't, but then I am not sure.
>3) Upgrade adds new packages to the system.
>4) Some packages increase in size with newer versions.
You forget:
5) When it computes the size of the packages it overestimates the
size by a fair amount, making upgrades fail more quickly than they
should. (Long standing bug)
>For a major upgrade install between releases, I agree it serves little
>purpose.
>I guess this is a corner usecase given that there's no convenient way to
>update selected packages in Neveda, it's either all or nothing right now,
>which I understand the reason.
That's because there is *NO* testing whatsoever of mixing and matching
between releases.
Note that when packages are installed with the exact same version, that
upgrade in principle can decide to leave them alone.
Casper
