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    SubjectRe: [ANNOUNCE] util-linux-ng v2.17 (stable)
    On Mon 2010-01-11 08:52:56, H. Peter Anvin wrote:
    > On 01/11/2010 06:05 AM, Pavel Machek wrote:
    > >On Fri 2010-01-08 13:43:47, H. Peter Anvin wrote:
    > >>On 01/08/2010 01:33 AM, Karel Zak wrote:
    > >>>
    > >>>fdisk:
    > >>> - the fdisk command aligns newly created partitions to minimum_io_size
    > >>> boundary ("minimum_io_size" is physical sector size or stripe chunk
    > >>> size on RAIDs).
    > >>>
    > >>> - the fdisk command supports disks with alignment_offset now.
    > >>>
    > >>
    > >>I think we should align, by default, much more aggressively than that --
    > >>because frequently we just don't know what the real physical alignment
    > >>is (think of flash media, which uses large erase blocks underneath.)
    > >
    > >Flash has special mapping layer, and does not care (SD/MMC), or is a
    > >raw nand and can't be used as block device (smartmedia).
    > >
    >
    > 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
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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