Hi Michael!
On Tue, Jan 25, 2005 at 08:04:14AM -0600, Dave Kleikamp <[EMAIL PROTECTED]>
wrote:
> On Tue, 2005-01-25 at 01:26 +0200, Hirsch, Michael wrote:
>
> > I saw dense files mentioned in some of the publications on the open
> > source JFS, but have not found a way of doing this from within the
> > docs, the code, the mkfs or the tune utility. I've tried to trace the
> > *SPARSE flags in the fs/jfs and jfsutils. I've tried searching the
> > jfs-*.mbox files on the official jfs website for "sparse" and "dense"
> > and "contiguous" but nothing turned up. Looked through the file
> > layout paper which has a great example of a sparse file, but I'm
> > looking for a dense example.
>
> jfs on Linux does not support the dense file option. The docs mention
> dense files because the code was originally ported from OS/2, where
> dense-file creation was the default behavior. At the time of the port,
> it seemed a reasonable thing to eventually support both dense and sparse
> options in Linux, as this would be more compatible with OS/2. As time
> went on, the dense file support was never much of a priority, and it
> probably won't be. Applications that would benefit from dense files can
> write a file sequentially when creating it, and get the same behavior.
If I understand right what you are looking for you could give
Reiser-FS a try. I have one partition with Reiser. It stores my copy
of the freecddb files: many many small text files.
[EMAIL PROTECTED]:~$ df -h /opt/cddb/
Dateisystem Gr��e Benut Verf Ben% Eingeh�ngt auf
/dev/ide/host0/bus0/target1/lun0/part3
2,5G 2,4G 29M 99% /opt/cddb
But du tells me that the amount of stored data is much much more.
[EMAIL PROTECTED]:~$ du -sch /opt/cddb/*
315M /opt/cddb/blues
89M /opt/cddb/cddbd
539M /opt/cddb/classical
20K /opt/cddb/COPYING
160M /opt/cddb/country
57M /opt/cddb/data
427M /opt/cddb/folk
367M /opt/cddb/jazz
2,0G /opt/cddb/misc
236M /opt/cddb/newage
4,0K /opt/cddb/README
78M /opt/cddb/reggae
1,9G /opt/cddb/rock
217M /opt/cddb/soundtrack
[+ around 500MB .tar.bz2 update files]
6,7G insgesamt
So it stores 6.7GB on a 2.5GB partition.
But as you can see
[EMAIL PROTECTED]:~$ ls -lh /opt/cddb/README /opt/cddb/COPYING
-rw-r--r-- 1 mm mueller 18K 1999-06-25 18:48 /opt/cddb/COPYING
-rw-r--r-- 1 mm mueller 1,7K 2002-08-03 22:39 /opt/cddb/README
COPYING is 18k but du counts it 20k and README is 1.7k but du counts
4k. I think du reports the size the file would use if it would use the
blocks for its own. But Reiser uses the unused bytes of one file to
store parts of another. Am I right?
Regards
Michael
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