The ECC enabled RAM should be very cheap quickly if the industry embraces it in every computer. :-)
best regards, hanzhu On Wed, Mar 31, 2010 at 5:46 PM, Erik Trimble <erik.trim...@oracle.com>wrote: > casper....@sun.com wrote: > >> >> >>> I'm not saying that ZFS should consider doing this - doing a validation >>> for in-memory data is non-trivially expensive in performance terms, and >>> there's only so much you can do and still expect your machine to survive. I >>> mean, I've used the old NonStop stuff, and yes, you can shoot them with a >>> .45 and it likely will still run, but wacking them with a bazooka still is >>> guarantied to make them, well, Non-NonStop. >>> >>> >> >> If we scrub the memory anyway, why not include the check of the ZFS >> checksums which are already in memory? >> >> OTOH, zfs gets a lot of mileage out of cheap hardware and we know what the >> limitations are when you don't use ECC; the industry must start to require >> that all chipsets support ECC. >> >> Caspe >> > Reading the paper was interesting, as it highlighted all the places where > ZFS "skips" validation. There's a lot of places. In many ways, fixing this > would likely make ZFS similar to AppleTalk whose notorious performance > (relative to Ethernet) was caused by what many called the "Are You Sure?" > design. Double and Triple checking absolutely everything has it's costs. > > And, yes, we really should just force computer manufacturers to use ECC in > more places (not just RAM) - as densities and data volumes increase, we are > more likely to see errors, and without proper hardware checking, we're > really going out on a limb here to be able to trust what the hardware says. > And, let's face it - hardware error correction is /so/ much faster than > doing it in software. > > > > > > > -- > Erik Trimble > Java System Support > Mailstop: usca22-123 > Phone: x17195 > Santa Clara, CA > Timezone: US/Pacific (GMT-0800) > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
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