Re: Reiserfs with Samba vs NetApp Filer

[Hans Reiser <reiser@namesys.com>]

Ragnar Kjørstad wrote:

>
>I think there the linux filesystems possible implement two very distinct
>features:
>- an (transactional?) object store (like the reiserfs tree)
>- and special objects; like directories, "inodes", EAs and so on
>
>I know that in some filesystems the distinction is not so clear (e.g. in
>ext2 where inodes have their specific place in the object-store).
>
>But my point is; would it not make sense to split up the filesystem-code
>(for the filesystems that would allow it) in the two parts mentioned
>above? Lustre is not alone in wanting a more low-level interface to the
>disk - I think this is very simular to the interface that squid uses, is
>it not?
>
>
>
>  
>

I was about to suggest to Andreas that his implementation on top of 
reiserfs is likely to be very inefficient unless he does something 
similar to our squid for reiserfs code (sponsored by someone who didn't 
continue sponsoring in the typical dotcom "more than nine months, no 
investor wants to wait that long for a return, give me a shorter 
timeline than that" fashion).

Andreas, very briefly, you want to find things in reiserfs by their 
keys, and you have no need for any directory entries at all, and having 
those directory entries will add substantial overhead.  Your metadata 
manager can probably track references, and if so there is no need for 
the FS to track it.

Unless you cut out directories you might even find that ext3 performs 
better because you can do lookups by inodes efficiently, and we can only 
do lookups by keys efficiently.

Hans