Why does `df` lie about free space (it doesn't)

[Jan Grant]

On Thu, 18 Mar 2004, Kyryll A Mirnenko wrote:

> >Using "tunefs -m". You need to be really careful doing this, and read
> >the man page for tunefs again, particularly the warning about how
> >lowering this number can trash your filesystem's performance.
>
>   I don't want that, I need to allow using preserved 8% of disk space
> to a little group of non-root users (for ex. postgres & rootty, my
> unprivileged user), but noone more. How do I do this?

You don't, without hacking filesystem code. The suggestion of another
poster to buy more disk is a good one.

> >PS. You keep on appearing to confuse the notion of free data >blocks with
> >free inodes. They're not the same thing: they are two distinct >resources
> >and your filesystem can run out of either pretty much >independently.
>
>   inode(5) descrbes inodes as a table of block addresses kinda FAT but
> with variable block sizes inodes point to. That is.

It's not really like FAT operation at all; but another responder has
given some detail along these lines.

-- 
jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287088 Fax +44 (0)117 9287112 http://ioctl.org/jan/
Theory and practice _are_ the same thing. In theory.