linux-kernel - Re: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion

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Date:	Tue, 25 Jul 2006 19:29:56 -0500
From:	David Masover <ninja@...phack.com>
To:	"Horst H. von Brand" <vonbrand@....utfsm.cl>
CC:	Mike Benoit <ipso@...ppymail.ca>,
	Matthias Andree <matthias.andree@....de>,
	Hans Reiser <reiser@...esys.com>, lkml@...productions.com,
	Jeff Garzik <jeff@...zik.org>, Theodore Tso <tytso@....edu>,
	LKML <linux-kernel@...r.kernel.org>,
	ReiserFS List <reiserfs-list@...esys.com>
Subject: Re: the " 'official' point of view" expressed by kernelnewbies.org
 regarding reiser4 inclusion

Horst H. von Brand wrote:

> 18GiB = 18 million KiB, you do have a point there. But 40 million files on
> that, with some space to spare, just doesn't add up.

Right, ok...

Here's a quick check of my box.  I've explicitly stated which root-level
directories to search, to avoid nfs mounts, chrooted OSes, and virtual
filesystems like /proc and /sys.

elite ~ # find /bin/ /boot/ /dev/ /emul/ /etc/ /home /lib32 /lib64 /opt
/root /sbin /tmp /usr /var -type f -size 1 | wc -l
246127

According to the "find" manpage:

-size n[bckw]
      File uses n units of space.  The units are  512-byte  blocks  by
      default  or  if `b' follows n, bytes if `c' follows n, kilobytes
      if `k' follows n, or 2-byte words if `w' follows  n.   The  size
      does  not  count  indirect  blocks,  but it does count blocks in
      sparse files that are not actually allocated.

And I certainly didn't plan it that way.  And this is my desktop box,
and I'm just one user.  Most of the space is taken up by movies.

And yet, I have almost 250k files at the moment whose size is less than
512 bytes.  And this is a normal usage pattern.  It's not hard to
imagine something prone to creating lots of tiny files, combined with
thousands of users, easily hitting some 40 mil files -- and since none
of them are movies, it could fit in 18 gigs.

I mean, just for fun:

elite ~ # find /bin/ /boot/ /dev/ /emul/ /etc/ /home /lib32 /lib64 /opt
/root /sbin /tmp /usr /var | wc -l
866160

It may not be a good idea, but it's possible.  And one of the larger
reasons it's not a good idea is that most filesystems can't handle it.
Kind of like how BitTorrent is a very bad idea on dialup, but a very
good idea on broadband.

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