Can somebody explain this? du & ls showing different sizes

[Patrick O'Callaghan]

On Sun, 2009-02-15 at 18:47 -0400, Felipe Nunez wrote:
>  
> 
> >Running du -h tells that the file occupies 512M but ls -l tells that
> 
> > the file is a lot smaller. Also I am sure the the cluster size is
> not
> 
> >512M (or am I wrong there?).
> 
>  In order to explain this behavior I did following test:
> 
> $ echo "hello" > hi.txt
> 
> $ ls -l hi.txt
> 
> -rw-r--r-- 1 user group 6 2009-02-15 18:37 download/hi.txt
> 
> (the size of the file is 6 bytes "hello" + '\n' )
> 
> $ du hi.txt
> 
> 4.0K hi.txt
> 
> (the size of the block -cluster is a MicroSoft equivalent term- is
> 4.0K)
> 
> That explains almost all. (Some data may be in memory in disk cache
> and can be some asynchrony with the file system)

That doesn't affect the result shown by 'du'. As far as it's concerned,
the space is allocated and therefore counts.

poc