Reiser4 bitmap & replication handling

["Fred -- Speed Up --" <speedup@free.fr>]

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I just read this article about XFS :
http://www-106.ibm.com/developerworks/library/l-fs9.html

It says XFS uses B+Trees as Reiser4 does, and it uses this structure to store not only the keys, but also the bitmap data and replicates it storage trees to improve scalability and overall wide-disk performance. It also tries to allocate the largest contigous blocks to a file (but Reiser4 does this also), and comes close to raw performance when reading large files. The article concludes XFS is faster than Reiser (3.6 I think, as the article has been published in 2002 by Gentoo CEO Daniel Robbins) with performance tweaks at mount time. But how does Reiser4 ?

How many times does Reiser replicate and/or truncate its tree, and what structure has been chosen for bitmap data ?
Does Reiser4 divide the disk space in chunks, as XFS and ext2 do ?
Are you implementing some special features for very large disks, RAID systems and multi-processing hardware ?
Is the developement far enough to get an idea of the final performance ? I didn't remember, when do you plan to release Reiser4 ?

I'm very interested in those brand new filesystem techniques, for now I think we can consider that XFS and Reiser3 are very close in overall performance. You're saying in the doc you'd like to keep on offering the best performance in the market : are you really that far ?

Fred