[lug] Do CD-TWs suck?

[Sean Reifschneider]

On Thu, Oct 27, 2005 at 03:10:11PM -0600, Zan Lynx wrote:
>I don't think it's a common problem.  I can't remember the last time a
>CD-R or RW or DVD-anything didn't work after I burned it.  I tend to buy
>the cheap stuff, too.

I have a bit of experience with this, since we burn something on the order
of a thousand CDs a month.  :-)  A couple of things up front though.  First
of all, drive quality seems to matter more than disc quality.  We send out
our CDs to people all over the world, and have found that even after we
burn and verify discs here, low quality discs have tended to fail on other
peoples drives.  We've even tested it to the point where we've had people
send back discs that were having issues to see if they got damaged in
transit, and they verified fine when we got them back.  Sending a
replacement set to them resolved it though.

And by "better drive" I'm not talking cost, our burners are mostly fairly
cheap drives.  I'm not advocating you all go out and buy Plextor drives, I
haven't really had that good of luck with the ones I've had in the past.
We mostly are using Mitsumi and TDK drives here and have been happy with
them.

The other thing is that just because you can read it doesn't mean that it's
a good burn.  Some marginal sectors the drive may be able to read after
spending many seconds or minutes trying hard at it.  IMHO, that burn is
"bad", it's just asking for trouble to rely on data on these, because as
the discs age these marginal sectors are likely to become hard to read
faster than the rest of the disc.  Your data integrity is only as strong as
it's weakest track, and all that jazz...

Now, on to media quality...  We had one drive that would reliably fail on
discs that our customers had problems with.  If we verified every disc
through this drive, we could be pretty sure that all our customers could
read them.

Around the time we were having these problems, I came up with a new
verification program which was much stricter about what it considered a
"bad" disc.  In our next burn cycle, we used this verification system and
discs we had from a fairly large manufacturer were showing 50% failures.
At first I worried that the verification system was having problems, but I
double checked it twice :-) and it seemed to be working as expected.  We
switched to using Taiyo Yuden discs, and since then have had absolutely no
problems.

Those discs were about twice the cost of the other discs, but with a 50%
failure rate, it was actually cheaper to use the more expensive discs.  Our
customer complaints about CD failures basically dropped off to nothing at
that point.

So, there *IS* a difference in disc quality.  I've seen it, absolutely.
I've had absolutely fantastic luck over the last 2 or 3 years with using
Taiyo Yuden discs.  If I had something important to store, that's all I'd
use.

Thanks,
Sean
-- 
 Every solution breeds new problems.
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995: Ask me about High Availability
      Back off man. I'm a scientist.   http://HackingSociety.org/