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    SubjectRe: [ANNOUNCE] util-linux-ng v2.17 (stable)
    On 01/11/2010 12:17 PM, Pavel Machek wrote:
    >>
    >> Uhm, that's just plain wrong.
    >>
    >> It doesn't matter if there is a "special mapping layer" -- if you're
    >> crossing multiple erase blocks you're still having more churn in
    >> your flash translation layer, with more wear on the device, and
    >> lower performance than if you didn't.
    >
    > Eraseblocks really should not matter. It is not as if each logical
    > sector belongs to one eraseblock....
    >
    > (OTOH, maybe the eraseblock *groups* that are basis for wear-leveling
    > do, or maybe firmware is doing something really really strange.)
    > Pavel

    Maybe they "should not" matter, but they *do* matter. In most existing
    FTLs, each logical sector *does* belong to one erase block, although
    which particular erase block that is of course moves around. However,
    the invariant that matters though -- and the reason alignment matters --
    is that for most FTLs, the *offset* of any particular logical sector
    within the erase block it currently belongs to is invariant, i.e. the
    FTL operates on physical sectors which are the same size as the erase
    blocks.

    -hpa


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