Re: Checksumming RAID?

[Roy Sigurd Karlsbakk <roy@karlsbakk.net>]

> > According to a few studies I've read, the number of silent errors
> > are identical on both consumer SATA drives and SAS drives. It's the
> > density that makes errors, and the platters and disk heads are
> > produced alike.
> 
> That's not what I'm reading:
> 
> Corruption detected in 8.5% of nearline disks, and 1.9% in enterprise
> disks.
> http://www.pdsi-scidac.org/events/PDSW09/resources/pdsw09_slides13.pdf

That doesn't make sense. Nearline and enterprise drives are large 7k2 drives that come in consumer and enterprise models, such as Hitachi Deskstar and Ultrastar. The latter is said to have better bearings etc, although I don't know the difference for sure. With WDs large drives, most of the difference is said to be in the firmware (such as TLER in the enterprise/RAID drives). Comparing "nearline" and "enterprise" like done here, is merely a comparison of small and large drives, where it's well known that the smaller (less dense) drives have less errors.

Vennlige hilsener / Best regards

roy
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Roy Sigurd Karlsbakk
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