Re: Seagate disk problems (NCQ bug???)

["Wolfgang S. Rupprecht" <wolfgang rupprecht+gnus200905 gmail com>]

"D. Hugh Redelmeier" <hugh mimosa com> writes:
> Could you dd an equivallent volume from /dev/zero to see if it also
> causes a problem?  That eliminates one more variable from the problem.

I'll try.  I have only seen it happen with a dvd as source.  Disk to
disk copies such as "cp -ax / /mnt/backup" didn't seem to cause
problems.

> Why do you call it "streaming conditions"?  Do you think that the fact
> that the DVD delivers bytes more slowly than the hard drive would accept
> them is important?  

I had assumed that the bug required a high sustained data rate that
would dump a large number of consecutive blocks into the disk's on-disk
cache, but was still slow enough to allow the on-disk cache to drain.

But then again, it was just a stab at explaining why it only seemed to
happen when reading from dvd.

> Or is there some other aspect that you think is relevant?

Hard to say.  I'd only really had 3 or 4 lockups and each time it was
the morning after I'd added a new video.

> NCQ has been around long enough that I'd expect/hope that the nits
> have been picked.  Of course I could be wrong.

Well, I've seen the bug described as a on-disk cache flushing bug and/or
NCQ bug.

In any case, Seagate support got me some SD3B firmware to load onto the
disk.  Strangely my disk now identifies itself as ST31500341AS instead
of ST31500343AS (with a "1" instead of a "3").  That also explains why I
couldn't find other folks with bug reports -- only a few drives went out
with the trailing "3" model number.  Lets see how the drive holds up.
I'm beating on it right now.

-wolfgang
-- 
Wolfgang S. Rupprecht              http://www.full-steam.org/  (ipv6-only)
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