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    SubjectRe: Journaling pointless with today's hard disks?
    Please fix your domain in your mailer, localhost.localdomain is prone
    for Message-ID collisions.

    Note, the power must RELIABLY last until all of the data has been
    writen, which includes reassigning, seeking and the like, just don't do
    it if you cannot get a real solution. battery-backed CMOS,
    NVRAM/Flash/whatever which lasts a couple of months should be fine
    though, as long as documents are publicly available that say how long
    this data lasts. Writing to disk will not work out unless you can keep
    the drive going for several seconds which will require BIG capacitors,
    so that's no option, you must go for NVRAM/Flash or something.

    OTOH, the OS must reliably know when something went wrong (even with
    good power it has a right to know), and preferably this scheme should
    not involve disabling the write cache, so TCQ or something mandatory
    would be useful (not sure if it's mandatory in current ATA standards).

    If a block has first been reported written OK and the disk later reports
    error, it must send the block back (incompatible with any current ATA
    draft I had my hands on), so I think tagged commands which are marked
    complete only after write+verify are the way to go.

    Matthias Andree

    "They that can give up essential liberty to obtain a little temporary
    safety deserve neither liberty nor safety." Benjamin Franklin
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