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    SubjectRe: [patch] document flash/RAID dangers
    Hi!

    > The other thing about this thread is that the only RAID implementation
    > that is being discussed here is the MD RAID stack. There are a lot of
    > RAID implementations that have the same issues:
    >
    > - motherboard (aka "fake") RAID - In Linux this is typically mapped with
    > device mapper via dmraid; AFAIK there is not a tool to scrub (or even
    > monitor the status of and notify on failure) a Linux DM RAID setup.
    >
    > - hardware RAID cards without battery backup - these have the exact same
    > issues because they cannot guarantee all writes complete, nor can they
    > keep track of incomplete writes across power failures
    >
    > - hardware RAID cards _with_ battery backup but that don't periodically
    > test the battery and have a way to notify you of battery failure while
    > Linux is running
    >
    > The issues being raised here are not specific to extX, MD RAID, or Linux
    > at all; they are problems with non-"enterprise-class" RAID setups.
    > There's a reason enterprise-class RAID costs a lot more money than the
    > card you can pick up at Fry's.
    >
    > There's no reason to document the design issues of general RAID
    > implementations in the Linux kernel.

    Even when we carry one of those misdesigned implementations in-tree?
    (Note that fixed implementations do exist -- AIX? -- just add journal).

    'I wont't tell you that this pony bites, because many ponies do bite'?

    WTF? I thought we had higher moral standard than this.

    Pavel

    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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