[mythtv-users] Hard Drive reliability esp. RAID issues

[Ronald Frazier]

Regarding this whole concept, I've never seen a good explanation that
doesn't gloss over the specifics. When they say unrecoverable read
error, I'm assuming they don't just mean a temporary read error (where
the next time we read it we'll get the correct value), as that would
be easy to deal with. So if we are talking about a permanently bad
sector, then I also assume this isn't just a case where we can scan
the drive ahead of time to find the problems, as again that would be
easy to deal with.

So I can only assume that what they mean is that, on average, after
every 12TB read 1 sector randomly turns up as permanently bad (1 bit
ruins the whole sector). But is this REALLY happening out there? Even
without raid, we should be seeing issues from this on high usage
devices. For example. A tivo is actually recording live tv 24x7, so
it's reading/writing 50+ TB/year. Thus it should be getting bad
sectors several times per year. Has anyone ever pulled a drive from a
several year old tivo and found a dozen or more bad sectors on it
(I've still got one that ran for 5 years or so, so maybe I should
check it just for kicks)? I wouldn't be surprised if I, myself, have
transferred enough data to have encountered such an error if this is
really happening, but in all the years I've yet to encounter such a
thing as randomly bad sectors (when a sector goes bad, usually the
rest of the drive isn't far behind, and that's a totally different
issue from the one being discussed here).

-- 
Ron