> Tomasz Chmielewski wrote:
> >For me, the motivators to wait for LogFS are mainly the facts that it
> >can work on traditional block devices, and not only on pure flash:
>
> Sorry Thomasz, for me this makes zero sense. There are _much_ better file
> systems for block devices. UBIFS may work on top of a block device as
> well (just needs few hacks to make it possible) - it is not a problem
> at all, it is just _senseless_.
>
> JFFS2/UBIFS/LogFS is a separate _class_ of file-systems. The are designed
> for _flash_, which has completely different work model then block device.
> They are _native_ flash file systems.
> Here are more details:
>
http://www.linux-mtd.infradead.org/faq/general.html#L_mtd_vs_hdd
>
> The traditional FSes _cannot_ work on top of flash. The solution for this
> is using FTL, which emulates a block device on top of flash. It _hides_ the
> real device, and fakes a block device for you. And you can use traditional
> FSes on top of that fake block device.
>
> The whole _point_ of this separate class of FSes is because we believe
> we may do much _better_ job if we use flash _natively_, instead of using
> FTL. FTL is the place where you loose performance, reliability, and so on.
>
> And you are saying about using a native flash FS on top of a block device
> like an SD card. This is just not sane: SD card first emulates a block
> device
> for you, looses performance at this point, then you again emulate a flash
> on top of this, and suffer from this again.
