[openbeos] Re: Max number of files on BFS?

"Mikael Jansson" <tic_khr@xxxxxxxx> wrote:
> Using either BFS or OpenBFS, what is, in real-life situations, the 
> highest number of files you can have on a) a BFS volume, and b) a 
> directory on a BFS volume?
> 
> Think: E-mail message archival on a 4.7 GB (== DVD size) BFS volume.
> 
> The reason I ask this is because I noticed my system got a lot faster 
> when I moved over all my email (10k files) to another volume than the 
> boot volume, and now I intend to keep it that way, because of the 
> ease-
> of-use when backing up (instead of having to do the zip -9ry dance.)

The size of the volume and its fragmentation also have an impact on the 
overall speed; the size because of the distance from index/log and file 
data, the fragmentation issue should be clear.
As François pointed out, BFS does not have a fixed maximum number of 
files. It also shouldn't noticeably slow down if there are 100,000 
files compared to 1,000 - as long as not all of them are emails :)
The B+trees in which BFS stores the directory and index data grow 
slowly in depth, and that's the only thing (apart from fragmentation) 
which would give a measureable but not necessarily noticeably speed 
impact.
In any way, the real problem of BFS is fragmentation - even if it does 
a pretty good job when positioning files and their data, B+tree 
fragmentation is also a problem (and BFS has nothing to fix that - if 
you have a directory with thousands of files and then delete all files, 
the B+tree size will not be cut down). An intelligent grouping of data 
and defragmentation tool could do wonder. It would all already exist if 
I wouldn't need to write Haiku :)

Bye,
   Axel.

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