[ILUG] Missing space

[Niall O Broin]

On 3 Mar 2006, at 13:24, Philip Trickett (List) wrote:

> Apparently, you might not want to set the reserved space to zero, as
> some of it is used for making sure that fragmentation does not become a
> problem. (Hey, I saw it linked off /. so it must be true...)

This "space reserved for the superuser" has been about for a long time 
- I first saw it on SunOS nearly 20 years ago. After many years of 
happily accepting the received wisdom, I decided that I really couldn't 
care if the disk could allocate space as efficiently as it got full - 
I'd sooner a little inefficient allocation rather than not being ab le 
to use space which is there.

So, I took to creating filesystems with no space reserved for root, and 
the policy has served me well since. When I started using Linux, I met 
my old friend the reserved space, and I again ignored him, to no ill 
effect.

Some time after I started doing this, I had the opportunity to discuss 
the wisdom of this with Remy Card, one of the authors of the ext2 code. 
He said that he did just as I did on some large busy FTP servers to to 
no ill effect. So I figure if it's good enough for him . . .

That all said, wouldn't you think that somebody who is clearly rather 
familiar with the principle of reserved space on a filesystem would 
think to check that when wondering where some space was gone :-(


Niall