one more question about nand

Al Johnson openmoko at
Wed Oct 28 18:40:06 CET 2009

On Wednesday 28 October 2009, Matthias Huber wrote:
> Nikita V. Youshchenko schrieb:
> >>> because i hadn't nderstood it in deep:
> >>>
> >>> when i would for example do an nand_erase on mtd6 and would make for
> >>> example an ext3 of it,
> >>>
> >>> would this work or is the jffs necessary for writing into nand (mtd6)
> >>> ?
> >>
> >> You may create ext3 on top of mtdblock6, however this will be slower
> >> than ext3, and cause fast nand chip wearing.
> >
> > slower than jffs2
> yes, was clear.  thank you.

Just for extra clarification, mtdblock devices are raw flash without wear 
levelling, so we want to use a filesystem like jffs2 that's designed with this 
in mind. uSD cards, CF, USB and SATA flash devices have wear levelling built 
into the controller hardware, so we can use any old filesystem.

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