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CD-R for long-term storage

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Anonymous
a b G Storage
April 23, 2004 11:19:55 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

There is a current article with interesting links about
this on /.:

http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...

The summary is essentially to forget it. Some testing with reasonably
conditions (dark cupboard) had unreadable media as soon as 2 years
after writing.

The problem seems to be that durability varies widely and there is no
way for ordinary users to asess media and writing quality (yes, a good
CD-R medium can be badly written and die early...). Mentioned
alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
(wishful thinking IMO, it has the same problems as CD-R), MOD
(phase-change, lifetime >50 years, but expensive), tape designed for
long-term storage (lifetime ~30 years, but this is not any of the
''cheap'' tapes like DAT) and keeping multiple copies with constant
checking and copying.

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus

More about : long term storage

Anonymous
a b G Storage
April 23, 2004 6:15:29 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

> The summary is essentially to forget it. Some testing with reasonably
> conditions (dark cupboard) had unreadable media as soon as 2 years
> after writing.
>
> The problem seems to be that durability varies widely and there is no
> way for ordinary users to asess media and writing quality (yes, a good
> CD-R medium can be badly written and die early...). Mentioned
> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> (wishful thinking IMO, it has the same problems as CD-R), MOD
> (phase-change, lifetime >50 years, but expensive), tape designed for
> long-term storage (lifetime ~30 years, but this is not any of the
> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> checking and copying.

Basically, use Mitsui Gold CD-R discs for the longest possible shelf life.

Otherwise, even the silver discs I have from 10 years ago are still
good. Only two out of thousands have gone bad in that time and the rest
of the discs are still readable w/o errors -- all stored in cold storage
w/o light exposure in a box.

---

http://www.silverace.com/dottyspotty/issue12.html

This issue contains advice on selecting quality CD-R discs to use when
recording/storing imporant data and photos for long-term storage.

0. Don't use CD-RW discs! They're only designed for short-term storage,
and are erasable. Don't go putting your imporant photos on these!

1. The dye used is probably the most important for long-term stability
and lifespan.

There are three dyes used today in CD-Rs, in order of preferece.

A. Phthalocyanine - inherently stable unlike cyanine dye which must
be stabilized by the addition of other metals, etc. Longest lasting
under testing. Expected lifespans exceeding 200+ years when coupled
with gold reflective layers in cold storage.

(color, light green on silver reflective surface; light
yellow/green on gold reflective surface)

B. Azo. Only Mitsubishi/Verbatim makes this. Up to 100 years,
less stable than Phthalocyanine dye, but more so than cyanine dye.

(color, very deep blue on silver reflective surface)

C. Cyanine dye. Chemically unstable alone, and must be stabilized.
Still, less stable than the other dyes in long-term simulation tests.
However, the first made consumer CD-Rs used this and is part of the
'standard' all CD-RW drives must be compatible with.

(color, green-blue/blue on silver)

2. You can use CDRIdentifier to read the dye information stored on the
CD-Rs you buy as well, which is more reliable if you don't know which
bottom colors represent which combinations.

CDRIdentifier: http://www.gum.de/it/download/english.htm

3. Besides dye, the reflective layer used affects long-term storage
lifespans.

There are three known types used today, in order of preference:
A. Gold - yep, expensive, but from the bottom, it'll look like real
gold.

B. Gold + Silver - Only Kodak Ultima Silver+Gold CD-Rs use this.
Their tests suggest this combination lasts longer than silver-looking
only discs.

C. silver. - not true silver, but silver looking. Most discs
produced today use this. However, given that metals except gold
corrode, corrosion of such surfaces (when the top laquer layer has been
removed/scratched) can and will occur.

4. Do not look at the top when trying to determing reflective layer
type! Look at the bottom in particular, the exposed areas around the
rim and inner hub. The fake 'gold' layer they put on top of some CD-Rs
are not true gold at all, and only there to 'fake' the customers.

5. The longest lasting CD-Rs, based on longevity testing, use
Phthalocyanine dye and Gold reflective layers. Phthalocyanine with
Gold&Silver reflective layers next, followed by Phthalocyanine and
Silver and Azo and Silver. Cyanine on anything (only silver today) is
the worst performing disc.

6. Typically, Japanese made CD-Rs tend have better quality control, IMO.
Once they move production to Taiwan/Mexico, forget em.

Top Quality Name-Brands, in order of preference:

A. Mitsui Gold CD-R & Kodak Gold Ultima - Phthalocyanine dye + Gold.
B. Kodak Gold Silver+Gold - Phthalocyanine dye + Silver & Gold.
C. Mitsui Silver, Ricoh Platinum - Phthalocyanine dye + Silver.
D. Mitsubishi/Verbatim - Azo + Silver.
E. Taiyo Yuden - Cyanine + Silver.

7. You can get these at www.cdrexpress.com and www.memorymedia.com.

Use www.silverace.com/smartpig/ to locate more places to buy, along with
online coupons, rebates, and ways to save money online.

8. All the other 'cheapies' not mentioned above are generally of poorer
& more variable quality. eg. those $15 / 100pk of no-name CD-Rs at
www.microcenter.com and www.compusa.com are the worst in long-term
longevity.

However, even the quality of cheapies today will last a few years
before deteriorating (assuming no long sunlight exposure; a few hours in
the sun will kill discs) and will work fine. Great for disposable
burns, music, and stuff you don't care if they fade away soon.

The poorest performing brand-name disc above, 6-#E, will still last
10-20 years in cold storage w/o any problems at all!

Remember to keep them away from sunlight/UV, and that most likely,
you'll be moving all of the data off CD-Rs onto newer storage medium
(maybe DVD-R? Holographic?) in 10-20 years. Why? Not one storage
medium has lived that long, and realistically, you'll want to move the
data off obsolete storage media =before= they stop making the drives!!

Just like nobody has 5 1/4" (or 8/12") floppy drives anymore,
expect only to need at the minimum discs that'll last until you migrate
the data off them in 10-20 years from now. Of course, higher quality,
longer lasting discs 6-#A-#D will only help your peace-of-mind.

9. Burn at least two copies of every important piece of data.
Preferably, to two different brands of discs, and preferably two
difference types (eg. Picking #A always is a good #1 pick, anything from
6-#B-#E as your #2). Although simulated longevity tests suggest #A has
the best lifepsan, nobody has ever sat around long enough yet to see if
that's true (in fact, CD-Rs have been out only about 10-15 years!).
Best to make sure you use two different brands and types to keep
bad-batches and combos of dyes/layers from ruining your data years from now.

10. Double-check all imporant discs after each burn - make sure they
match the original files 100% before putting them away and assuming
they're good burns. Use the CD-R program's 'verify-after-write'
feature, available in only some programs, or CDCheck:
http://fusion.zejn.si/ to do this.
Anonymous
a b G Storage
April 23, 2004 6:17:34 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

From my experience: you get what you pay for. I've only had cheap white
disks (memorex) failed after a few years. Some blank media would not even
record after been stored for a year. Some DVD-R Memorex media also would not
record after a year.
Blue disks from good brands (TDK) are still OK.

I think, too, that phase-change media must be more stable.

"Arno Wagner" <me@privacy.net> wrote in message
news:c6ag2r$9p9cb$1@ID-2964.news.uni-berlin.de...
> There is a current article with interesting links about
> this on /.:
>
>
http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>
> The summary is essentially to forget it. Some testing with reasonably
> conditions (dark cupboard) had unreadable media as soon as 2 years
> after writing.
>
> The problem seems to be that durability varies widely and there is no
> way for ordinary users to asess media and writing quality (yes, a good
> CD-R medium can be badly written and die early...). Mentioned
> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> (wishful thinking IMO, it has the same problems as CD-R), MOD
> (phase-change, lifetime >50 years, but expensive), tape designed for
> long-term storage (lifetime ~30 years, but this is not any of the
> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> checking and copying.
>
> Arno
> --
> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
> "The more corrupt the state, the more numerous the laws" - Tacitus
>
>
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Anonymous
a b G Storage
April 23, 2004 7:40:43 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

In article <c6ag2r$9p9cb$1@ID-2964.news.uni-berlin.de>,
me@privacy.net says...
> There is a current article with interesting links about
> this on /.:
>
> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>
> The summary is essentially to forget it. Some testing with reasonably
> conditions (dark cupboard) had unreadable media as soon as 2 years
> after writing.
>
> The problem seems to be that durability varies widely and there is no
> way for ordinary users to asess media and writing quality (yes, a good
> CD-R medium can be badly written and die early...). Mentioned
> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> (wishful thinking IMO, it has the same problems as CD-R), MOD
> (phase-change, lifetime >50 years, but expensive), tape designed for
> long-term storage (lifetime ~30 years, but this is not any of the
> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> checking and copying.
>

I've said it before, but it's also a smart idea to add
recovery data (e.g. PAR2s created by QuickPar) to any
sort of archival media. Gives you a bit more safety net
then the built-in error correction on the media, allows
you to verify the contents of the media, and you can
pick how paranoid you want to be. (For low-paranoia,
only create 5% recovery data, for high-paranoia create
100% recovery data and burn multiple copies.)
Anonymous
a b G Storage
April 24, 2004 12:44:32 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Arno Wagner <me@privacy.net> wrote in message
news:c6ag2r$9p9cb$1@ID-2964.news.uni-berlin.de...

> There is a current article with interesting links about this on /.:

> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...

> The summary is essentially to forget it.

Stupid summary then.

> Some testing with reasonably conditions (dark cupboard)
> had unreadable media as soon as 2 years after writing.

And I havent lost a single one over a much longer period
than that, with no care taken at all, in fact some stored
in jewel cases where they get full sunlight in winter too.

> The problem seems to be that durability varies widely and there
> is no way for ordinary users to asess media and writing quality

So the obvious thing to do with data that matters is to write
it on more than one brand of media and do some basic error
checks to ensure that it is at least written properly.

> (yes, a good CD-R medium can be badly written and die early...).

And its completely trivial to check if its been badly written.

> Mentioned alternatives are CD-RW (not dye-based,
> lifetime unknowen), DVD+/-R (wishful thinking IMO,
> it has the same problems as CD-R),

And you've always had silly ideas about all these media.

> MOD (phase-change, lifetime >50 years,

We dont know that yet.

> but expensive),

Makes more sense to use multiple cheap approaches instead.

> tape designed for long-term storage (lifetime ~30 years,

We dont know that yet either.

> but this is not any of the ''cheap'' tapes like DAT) and
> keeping multiple copies with constant checking and copying.

Which is much more viable with CD/DVD formats, stupid.
Anonymous
a b G Storage
April 25, 2004 2:14:21 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Arno Wagner wrote:
>
> There is a current article with interesting links about
> this on /.:
>
> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>
> The summary is essentially to forget it. Some testing with reasonably
> conditions (dark cupboard) had unreadable media as soon as 2 years
> after writing.
>
> The problem seems to be that durability varies widely and there is no
> way for ordinary users to asess media and writing quality (yes, a good
> CD-R medium can be badly written and die early...). Mentioned
> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> (wishful thinking IMO, it has the same problems as CD-R), MOD
> (phase-change, lifetime >50 years, but expensive), tape designed for
> long-term storage (lifetime ~30 years, but this is not any of the
> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> checking and copying.
>
> Arno
> --
> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
> "The more corrupt the state, the more numerous the laws" - Tacitus


Hello, Arno:

Don't forget DVD-RAM, please. It's on a par with your precious MOD,
after all. :-P


Cordially,
John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 25, 2004 11:00:58 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

John Turco wrote:

> Arno Wagner wrote:
>>
>> There is a current article with interesting links about
>> this on /.:
>>
>>
http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>>
>> The summary is essentially to forget it. Some testing with reasonably
>> conditions (dark cupboard) had unreadable media as soon as 2 years
>> after writing.
>>
>> The problem seems to be that durability varies widely and there is no
>> way for ordinary users to asess media and writing quality (yes, a good
>> CD-R medium can be badly written and die early...). Mentioned
>> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
>> (wishful thinking IMO, it has the same problems as CD-R), MOD
>> (phase-change, lifetime >50 years, but expensive), tape designed for
>> long-term storage (lifetime ~30 years, but this is not any of the
>> ''cheap'' tapes like DAT) and keeping multiple copies with constant
>> checking and copying.
>>
>> Arno
>> --
>> For email address: lastname AT tik DOT ee DOT ethz DOT ch
>> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
>> "The more corrupt the state, the more numerous the laws" - Tacitus
>
>
> Hello, Arno:
>
> Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> after all. :-P

Uh, why would that be?

>
>
> Cordially,
> John Turco <jtur@concentric.net>

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
April 25, 2004 9:52:53 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

DVD-RAM is phase-change technology, and is likely equal to DVD-RW in
longevity.

"John Turco" <jtur@concentric.net> wrote in message
news:408B1EEF.1418E4D@concentric.net...
>
>
> Hello, Arno:
>
> Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> after all. :-P
>
>
> Cordially,
> John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 25, 2004 10:19:37 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Previously John Turco <jtur@concentric.net> wrote:
> Arno Wagner wrote:
>>
>> There is a current article with interesting links about
>> this on /.:
>>
>> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>>
>> The summary is essentially to forget it. Some testing with reasonably
>> conditions (dark cupboard) had unreadable media as soon as 2 years
>> after writing.
>>
>> The problem seems to be that durability varies widely and there is no
>> way for ordinary users to asess media and writing quality (yes, a good
>> CD-R medium can be badly written and die early...). Mentioned
>> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
>> (wishful thinking IMO, it has the same problems as CD-R), MOD
>> (phase-change, lifetime >50 years, but expensive), tape designed for
>> long-term storage (lifetime ~30 years, but this is not any of the
>> ''cheap'' tapes like DAT) and keeping multiple copies with constant
>> checking and copying.
>>
>> Arno
>> --
>> For email address: lastname AT tik DOT ee DOT ethz DOT ch
>> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
>> "The more corrupt the state, the more numerous the laws" - Tacitus


> Hello, Arno:

> Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> after all. :-P

Well, yes. If you can get a drive that accepts the version with
cartridge... (Yes, I know. They are out there. Just difficult to
find. And my critical system backups still fit on a pair of 640MB
MOD's each.)

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus
Anonymous
a b G Storage
April 25, 2004 10:19:38 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Arno Wagner wrote:

> Previously John Turco <jtur@concentric.net> wrote:
>> Arno Wagner wrote:
>>>
>>> There is a current article with interesting links about
>>> this on /.:
>>>
>>>
http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>>>
>>> The summary is essentially to forget it. Some testing with reasonably
>>> conditions (dark cupboard) had unreadable media as soon as 2 years
>>> after writing.
>>>
>>> The problem seems to be that durability varies widely and there is no
>>> way for ordinary users to asess media and writing quality (yes, a good
>>> CD-R medium can be badly written and die early...). Mentioned
>>> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
>>> (wishful thinking IMO, it has the same problems as CD-R), MOD
>>> (phase-change, lifetime >50 years, but expensive), tape designed for
>>> long-term storage (lifetime ~30 years, but this is not any of the
>>> ''cheap'' tapes like DAT) and keeping multiple copies with constant
>>> checking and copying.
>>>
>>> Arno
>>> --
>>> For email address: lastname AT tik DOT ee DOT ethz DOT ch
>>> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
>>> "The more corrupt the state, the more numerous the laws" - Tacitus
>
>
>> Hello, Arno:
>
>> Don't forget DVD-RAM, please. It's on a par with your precious MOD,
>> after all. :-P
>
> Well, yes. If you can get a drive that accepts the version with
> cartridge... (Yes, I know. They are out there. Just difficult to
> find. And my critical system backups still fit on a pair of 640MB
> MOD's each.)

FWIW, the protection provided by that cartridge is questionable. Was
watching a demo one time of a machine with an MO drive in it. The drive
wouldn't read. While the presenter was off hunting up the tech, I opened
the slider on the cartridge and took a look inside. Just as I suspected,
full of dried coffee.

> Arno

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
April 25, 2004 10:23:57 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Toshi1873 wrote:


> I've said it before, but it's also a smart idea to add
> recovery data (e.g. PAR2s created by QuickPar) to any
> sort of archival media. Gives you a bit more safety net
> then the built-in error correction on the media, allows
> you to verify the contents of the media, and you can
> pick how paranoid you want to be. (For low-paranoia,
> only create 5% recovery data, for high-paranoia create
> 100% recovery data and burn multiple copies.)


Can QuickPar be really be that helpful for imaging software, though?
To me, it appears to be helpful when you have something that is split
into many smaller files. So if one file is missing or cannot be read,
QuickPar can reconstruct the missing data.

But what about the case where you have a single image file on a DVD-RW.
And part of the disc got a scratch on it. Can QuickPar help in such
a case?


-WD
Anonymous
a b G Storage
April 26, 2004 1:53:07 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

In article <1nTic.13525$3_1.4068@fe2.columbus.rr.com>,
wdormann@yahoo.com.invalid says...
> Toshi1873 wrote:
> > I've said it before, but it's also a smart idea to add
> > recovery data (e.g. PAR2s created by QuickPar) to any
> > sort of archival media. Gives you a bit more safety net
> > then the built-in error correction on the media, allows
> > you to verify the contents of the media, and you can
> > pick how paranoid you want to be. (For low-paranoia,
> > only create 5% recovery data, for high-paranoia create
> > 100% recovery data and burn multiple copies.)
>
> Can QuickPar be really be that helpful for imaging software, though?
> To me, it appears to be helpful when you have something that is split
> into many smaller files. So if one file is missing or cannot be read,
> QuickPar can reconstruct the missing data.
>
> But what about the case where you have a single image file on a DVD-RW.
> And part of the disc got a scratch on it. Can QuickPar help in such
> a case?

So long as the ToC isn't damaged, you can rip the entire
disc to an ISO file using something like ISOBuster.
(Damaged sectors and all.) QuickPar will then root
through the ISO file and extract all of the useable data
blocks and recovery blocks. Peter has a page somewhere
on hit site (or in the forums) explaining how to do an
ISOBuster-style recovery.
Anonymous
a b G Storage
April 26, 2004 6:46:47 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"J. Clarke" wrote:
>
> John Turco wrote:
>
> > Arno Wagner wrote:
> >>
> >> There is a current article with interesting links about
> >> this on /.:
> >>
> >>
> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
> >>
> >> The summary is essentially to forget it. Some testing with reasonably
> >> conditions (dark cupboard) had unreadable media as soon as 2 years
> >> after writing.
> >>
> >> The problem seems to be that durability varies widely and there is no
> >> way for ordinary users to asess media and writing quality (yes, a good
> >> CD-R medium can be badly written and die early...). Mentioned
> >> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> >> (wishful thinking IMO, it has the same problems as CD-R), MOD
> >> (phase-change, lifetime >50 years, but expensive), tape designed for
> >> long-term storage (lifetime ~30 years, but this is not any of the
> >> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> >> checking and copying.
> >>
> >> Arno
> >> --
> >> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> >> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
> >> "The more corrupt the state, the more numerous the laws" - Tacitus
> >
> >
> > Hello, Arno:
> >
> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> > after all. :-P
>
> Uh, why would that be?
>
> >
> >
> > Cordially,
> > John Turco <jtur@concentric.net>
>
> --
> --John
> Reply to jclarke at ae tee tee global dot net
> (was jclarke at eye bee em dot net)


Hello, John:

Here's an example, from "TheFreeDictionary.com"
<http://www.thefreedictionary.com&gt;:

DVD-RAM - encyclopedia article about DVD-RAM
<http://encyclopedia.thefreedictionary.com/DVD-RAM&gt;

"DVD-RAM is considered a highly reliable format, as the discs use
aspects of both phase change and magneto-optical technologies and
have built-in error control."

That's why! <g>


Cordially,
John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 26, 2004 6:46:49 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Alexander Grigoriev wrote:
>
> DVD-RAM is phase-change technology, and is likely equal to DVD-RW in
> longevity.


Hello, Alexander:

Which is "25 to 100 years," from what I've read. Pretty good, no?


Cordially,
John Turco <jtur@concentric.net>


> "John Turco" <jtur@concentric.net> wrote in message
> news:408B1EEF.1418E4D@concentric.net...
> >
> >
> > Hello, Arno:
> >
> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> > after all. :-P
> >
> >
> > Cordially,
> > John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 26, 2004 6:46:50 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Arno Wagner wrote:
>
> Previously John Turco <jtur@concentric.net> wrote:
> > Arno Wagner wrote:
> >>
> >> There is a current article with interesting links about
> >> this on /.:
> >>
> >> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
> >>
> >> The summary is essentially to forget it. Some testing with reasonably
> >> conditions (dark cupboard) had unreadable media as soon as 2 years
> >> after writing.
> >>
> >> The problem seems to be that durability varies widely and there is no
> >> way for ordinary users to asess media and writing quality (yes, a good
> >> CD-R medium can be badly written and die early...). Mentioned
> >> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> >> (wishful thinking IMO, it has the same problems as CD-R), MOD
> >> (phase-change, lifetime >50 years, but expensive), tape designed for
> >> long-term storage (lifetime ~30 years, but this is not any of the
> >> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> >> checking and copying.
> >>
> >> Arno
> >> --
> >> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> >> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
> >> "The more corrupt the state, the more numerous the laws" - Tacitus
>
> > Hello, Arno:
>
> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> > after all. :-P
>
> Well, yes. If you can get a drive that accepts the version with
> cartridge... (Yes, I know. They are out there. Just difficult to
> find. And my critical system backups still fit on a pair of 640MB
> MOD's each.)
>
> Arno
> --
> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
> "The more corrupt the state, the more numerous the laws" - Tacitus


Hello, Arno:

Well, I'm sure cartridges provide protection against the rough-handling
of everyday use; I was referring to "shelf life," actually.

Also, I concur that such media is a bit scarce, at "brick-and-mortar"
stores. It's more plentiful at online merchants, logically enough.


Cordially,
John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 26, 2004 6:56:13 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Toshi1873 wrote:

> In article <1nTic.13525$3_1.4068@fe2.columbus.rr.com>,
> wdormann@yahoo.com.invalid says...
>
>>But what about the case where you have a single image file on a DVD-RW.
>> And part of the disc got a scratch on it. Can QuickPar help in such
>>a case?
>
>
> So long as the ToC isn't damaged, you can rip the entire
> disc to an ISO file using something like ISOBuster.
> (Damaged sectors and all.) QuickPar will then root
> through the ISO file and extract all of the useable data
> blocks and recovery blocks. Peter has a page somewhere
> on hit site (or in the forums) explaining how to do an
> ISOBuster-style recovery.

Ahh, that makes sense. Thanks.


-WD
Anonymous
a b G Storage
April 26, 2004 7:43:54 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Previously J. Clarke <jclarke@nospam.invalid> wrote:
> Arno Wagner wrote:
[..]
> FWIW, the protection provided by that cartridge is questionable. Was
> watching a demo one time of a machine with an MO drive in it. The drive
> wouldn't read. While the presenter was off hunting up the tech, I opened
> the slider on the cartridge and took a look inside. Just as I suspected,
> full of dried coffee.

Yes, that cartridge is not really sealed. It is more protection
against a fall, scratches or fingerprints. It offers limited
protection against dust, but no protection from fluid. However
removing coffee is relatively easy: Just rinse with water and
dry off (don't rub) with soft paper-towels. Same as CD/DVD. The
cartridges (at least the ones I have) can be openend and re-closed
with a screwdriver.

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus
Anonymous
a b G Storage
April 27, 2004 11:54:39 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

John Turco wrote:

> "J. Clarke" wrote:
>>
>> John Turco wrote:
>>
>> > Arno Wagner wrote:
>> >>
>> >> There is a current article with interesting links about
>> >> this on /.:
>> >>
>> >>
>>
http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>> >>
>> >> The summary is essentially to forget it. Some testing with reasonably
>> >> conditions (dark cupboard) had unreadable media as soon as 2 years
>> >> after writing.
>> >>
>> >> The problem seems to be that durability varies widely and there is no
>> >> way for ordinary users to asess media and writing quality (yes, a good
>> >> CD-R medium can be badly written and die early...). Mentioned
>> >> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
>> >> (wishful thinking IMO, it has the same problems as CD-R), MOD
>> >> (phase-change, lifetime >50 years, but expensive), tape designed for
>> >> long-term storage (lifetime ~30 years, but this is not any of the
>> >> ''cheap'' tapes like DAT) and keeping multiple copies with constant
>> >> checking and copying.
>> >>
>> >> Arno
>> >> --
>> >> For email address: lastname AT tik DOT ee DOT ethz DOT ch
>> >> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25
>> >> 338F
>> >> "The more corrupt the state, the more numerous the laws" - Tacitus
>> >
>> >
>> > Hello, Arno:
>> >
>> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
>> > after all. :-P
>>
>> Uh, why would that be?
>>
>> >
>> >
>> > Cordially,
>> > John Turco <jtur@concentric.net>
>>
>> --
>> --John
>> Reply to jclarke at ae tee tee global dot net
>> (was jclarke at eye bee em dot net)
>
>
> Hello, John:
>
> Here's an example, from "TheFreeDictionary.com"
> <http://www.thefreedictionary.com&gt;:
>
> DVD-RAM - encyclopedia article about DVD-RAM
> <http://encyclopedia.thefreedictionary.com/DVD-RAM&gt;
>
> "DVD-RAM is considered a highly reliable format, as the discs use
> aspects of both phase change and magneto-optical technologies and
> have built-in error control."
>
> That's why! <g>

You might want to develop the habit of seeking more authoritative sources
than "TheFreeDictionary". For example see the discussion at
<http://www.pioneer.co.jp/crdl/tech/dvd/7-e.html&gt; (noting that Pioneer
actually makes the hardware) in which it is made clear that DVD-RAM is a
phase change technology little different in its physics and chemistry from
DVD-RW. Further, it uses the same ECC algorithm as DVD-R and DVD-RW.
Neither of these would suggest higher reliability than DVD-RW. The major
difference is in the formatting, which in DVD-RAM is designed to facilitate
random access, and there is no reason to believe that that formatting
difference would increase long-term stability.

Further, if it's "on a par with magneto optical" you surely have access to
some test results which demonstrate this.

> Cordially,
> John Turco <jtur@concentric.net>

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Anonymous
a b G Storage
April 28, 2004 3:53:45 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"J. Clarke" wrote:
>
> John Turco wrote:
>
> > "J. Clarke" wrote:
> >>
> >> John Turco wrote:
> >>
> >> > Arno Wagner wrote:
> >> >>
> >> >> There is a current article with interesting links about
> >> >> this on /.:
> >> >>
> >> >>
> >>
> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
> >> >>
> >> >> The summary is essentially to forget it. Some testing with reasonably
> >> >> conditions (dark cupboard) had unreadable media as soon as 2 years
> >> >> after writing.
> >> >>
> >> >> The problem seems to be that durability varies widely and there is no
> >> >> way for ordinary users to asess media and writing quality (yes, a good
> >> >> CD-R medium can be badly written and die early...). Mentioned
> >> >> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> >> >> (wishful thinking IMO, it has the same problems as CD-R), MOD
> >> >> (phase-change, lifetime >50 years, but expensive), tape designed for
> >> >> long-term storage (lifetime ~30 years, but this is not any of the
> >> >> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> >> >> checking and copying.
> >> >>
> >> >> Arno
> >> >> --
> >> >> For email address: lastname AT tik DOT ee DOT ethz DOT ch
> >> >> GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25
> >> >> 338F
> >> >> "The more corrupt the state, the more numerous the laws" - Tacitus
> >> >
> >> >
> >> > Hello, Arno:
> >> >
> >> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
> >> > after all. :-P
> >>
> >> Uh, why would that be?
> >>
> >> >
> >> >
> >> > Cordially,
> >> > John Turco <jtur@concentric.net>
> >>
> >> --
> >> --John
> >> Reply to jclarke at ae tee tee global dot net
> >> (was jclarke at eye bee em dot net)
> >
> >
> > Hello, John:
> >
> > Here's an example, from "TheFreeDictionary.com"
> > <http://www.thefreedictionary.com&gt;:
> >
> > DVD-RAM - encyclopedia article about DVD-RAM
> > <http://encyclopedia.thefreedictionary.com/DVD-RAM&gt;
> >
> > "DVD-RAM is considered a highly reliable format, as the discs use
> > aspects of both phase change and magneto-optical technologies and
> > have built-in error control."
> >
> > That's why! <g>
>
> You might want to develop the habit of seeking more authoritative sources
> than "TheFreeDictionary".

Hello, John:

No "habit" involved...I merely did a quick Google search, and picked
one of the results. Besides, did "TheFreeDictionary" say anything wrong,
concerning DVD-RAM?

For further information, please look up this article, on Google Groups
<http://groups.google.com&gt;:

"RADAR 24 & DVD-RAM Technology/Future" (2002-03-24 16:32:42 PST)

>For example see the discussion at
> <http://www.pioneer.co.jp/crdl/tech/dvd/7-e.html&gt; (noting that Pioneer
> actually makes the hardware) in which it is made clear that DVD-RAM is a
> phase change technology little different in its physics and chemistry from
> DVD-RW.

Panasonic "makes the hardware," also. So what? Has either company
implied that DVD-RAM is somehow deficient?

On the contrary, Panasonic has always pushed DVD-RAM, to supplement its
sagging MOD business!

>Further, it uses the same ECC algorithm as DVD-R and DVD-RW.
> Neither of these would suggest higher reliability than DVD-RW. The major
> difference is in the formatting, which in DVD-RAM is designed to facilitate
> random access, and there is no reason to believe that that formatting
> difference would increase long-term stability.

Really? Well, then, are you aware that "packet writing" software -
required by DVD-R and DVD-RW, alike, in order give them "random access"
capabilities - tends to be rather flaky, at times?

> Further, if it's "on a par with magneto optical" you surely have access to
> some test results which demonstrate this.
>
> > Cordially,
> > John Turco <jtur@concentric.net>
>
> --
> --John
> Reply to jclarke at ae tee tee global dot net
> (was jclarke at eye bee em dot net)

"Test results?" I'm not running a laboratory, here!

Nonetheless, the fact there's an abundance of "el cheapo" DVD-RW/DVD+RW
"brands" in existence, would lead one to doubt the average quality of
such media.

Don't see quite the same situation, regarding DVD-RAM, do you? (Check
"Price Watch" <http://www.pricewatch.com&gt;, if you need convincing.)


Cordially,
John Turco <jtur@concentric.net>
Anonymous
a b G Storage
April 28, 2004 9:56:19 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Arno Wagner <me@privacy.net> wrote in message news:<c6ag2r$9p9cb$1@ID-2964.news.uni-berlin.de>...
> There is a current article with interesting links about
> this on /.:
>
> http://slashdot.org/article.pl?sid=04/04/22/1658251&mod...
>
> The summary is essentially to forget it. Some testing with reasonably
> conditions (dark cupboard) had unreadable media as soon as 2 years
> after writing.
>
> The problem seems to be that durability varies widely and there is no
> way for ordinary users to asess media and writing quality (yes, a good
> CD-R medium can be badly written and die early...). Mentioned
> alternatives are CD-RW (not dye-based, lifetime unknowen), DVD+/-R
> (wishful thinking IMO, it has the same problems as CD-R), MOD
> (phase-change, lifetime >50 years, but expensive), tape designed for
> long-term storage (lifetime ~30 years, but this is not any of the
> ''cheap'' tapes like DAT) and keeping multiple copies with constant
> checking and copying.
>
> Arno

Fujitsu MO drives aren't that expensive and the media is very stable
as I've been using them since 1997 and have not lost any data. You can
get the newest 1.3 gig usb powered drive for around $200 and a five
pack of disks from Provantage.com (they have the cheapest) are less
than $50 shipped. Make sure they are the Fujitsu disks as they are the
least expensive.

I love my MO drives and only use CDR for music or if I need to share
data since with someone since no one I know has an MO drive.
Anonymous
a b G Storage
May 2, 2004 6:25:56 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

John Turco wrote:

> Alexander Grigoriev wrote:
>>
>> DVD-RAM is phase-change technology, and is likely equal to DVD-RW in
>> longevity.
>
>
> Hello, Alexander:
>
> Which is "25 to 100 years," from what I've read. Pretty good, no?

So you admit that the longevity is the same as for DVD-RW? Doesn't that
make DVD-RW also "on a par with your precious MOD"? If so then you've just
defeated your own argument.

Further, that prediction is from accelerated aging studies, which are valid
only if they accurately reflect the factors that lead to failure. Since
DVDs have not been around for 100 years, the designers of such studies are
necessarily guessing at what they have to test, and their guesses may or
may not be accurate. The same concern applies for MOD, however MOD has
been available as a commercial product longer than phase-change optical, so
its failure modes may be slightly better understood.

>
> Cordially,
> John Turco <jtur@concentric.net>

>> "John Turco" <jtur@concentric.net> wrote in message
>> news:408B1EEF.1418E4D@concentric.net...
>> >
>> >
>> > Hello, Arno:
>> >
>> > Don't forget DVD-RAM, please. It's on a par with your precious MOD,
>> > after all. :-P
>> >
>> >
>> > Cordially,
>> > John Turco <jtur@concentric.net>

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
!