On Tue, Dec 19, 2000 at 09:25:27AM -0800, Jason R Thorpe wrote:
> On Tue, Dec 19, 2000 at 01:03:42AM -0500, Andrew Brown wrote:
>  > i'm just curious...would it be trivial to modify these tools to use a
>  > hierarchical arrangement of files a directories as well (eg, instead
>  > of opening file "1234567", one would open "12/34/567")?  i'd be
>  > curious to see the difference there, since that was the usual attack
>  > against the problem.
> 
> Right, well, what that does is help to address the problem of directory
> lookups being linear searches in FFS.
> 
> We need an FFSng that has tree-structured directories.

Would something akin to the technique NetApp describe in the following
paper be useful?
	Accelerated Performance for Large Directories
	http://www.netapp.com/tech_library/3006.html

Didn't require on-disk format changes, although their directory
structure was slightly different from FFS when they made that change.

BTW: I didn't realise that softdep had solved at least a chunk of the
performance issues with large directories. That's good to know.

Luke.

-- 
Luke Mewburn  <lukem@wasabisystems.com>  http://www.wasabisystems.com
Luke Mewburn     <lukem@netbsd.org>      http://www.netbsd.org
Wasabi Systems - providing NetBSD sales, support and service.