Re: df and du don't seem to agree ?

[Camaleón <noelamac@gmail.com>]

On Tue, 21 Aug 2012 16:45:35 +0200, David Cho-Lerat wrote:

> this might be a newbie question, but can anyone tell me why "du" and
> "df" don't seem to agree :
> 
> server:~# df -h /var
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/mapper/vg00-var  5.0G  4.1G  624M  87% /var 
> server:~# du -h -s /var 
> 1.6G    /var
> 
> ("/var" is on a partition of its own.)
> 
> "du" says 1.6G are used, while "df" reports 4.1G. Any idea why ?
> 
> I know some amount of space is supposed to be "reserved for the
> super-user", but that's typically around 5%, right ?

Right.

Google returns:

http://superuser.com/questions/289678/du-vs-df-output

> By the way, is there a command to see how big this reserved space
> actually is on a given partition/disk ?

With a simple math calculation ;-P

5% of 5 GiB are ~256 MiB of reserved space.

Greetings,

-- 
Camaleón