Re: ReiserFS on large-scale flash

["Artem B. Bityuckiy" <dedekind@yandex.ru>]

Just few refinements.

Traditionally an emulation layer is created on top of flash. This layer 
hides Flash limitations and emulates block device on top of flash. But 
this approach is highly inefficient and is not usable in most system. We 
need an FS which is aware of the differences. Like JFFS2, but JFFS2 
doesn't scale (not usable starting from about 256MiB flash).

Artem B. Bityuckiy wrote:
> Hello,
> 
> I'm designing new flash file system. And I'm thinking about the 
> possibility to write plugins for ReiserFS to implement it (I know, it 
> sounds crazy). I didn't thoroughly explore is it possible or not yet.
> 
> I'm almost certain that it is impossible to do this with the current 
> Reiser4 and more changes are needed. Flash devices just has another 
> model, not the same as block devices. In a nutshell, you can't write 
> twice to the same block (out-of-place writing property) and you must 
> erase a several consecutive blocks before re-using any block (read here: 
> http://en.wikipedia.org/wiki/Flash_memory).
> 
> Currently there are no Flash file systems which are usable on large 
> scale flashes, at least in Linux. And there is a real need in such FS.
> 
> So, I'd like to know, are Reisre4 developers interested in this? Will I 
> have some assistance from them if I find some Reiser4 limitation? Is it 
> worth starting exploring Reiser4 or better just start new FS?
> 
> Thanks.
> 

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.