I need to measure the exact size of some installation.
For example, I need to know the disk usage of
apt install vim.
My idea is to install a clean Ubuntu first, then I measure the size of its filesystem (x KB); After that, I do
apt install pkgname and measure the size of its filesystem (y KB) again.
So the disk usage of
apt install pkgname =
y - xKB.
However, there are some virtual directories, such as
/proc, so I don't know how to measure the exact size of the filesystem. Also, when we do
apt install pkgname, a
deb file will be downloaded in
/var/cache/apt/archives/, so I don't know how to measure exactly the disk usage for