CD-R Warning, if ever one were needed.

[JKirbs]

Hi all!

This would be better news to report if anything were discussed about DVD media that we all use, but i think it's a worthwhile reminder nonetheless, and worth considering:

http://computerworld.com/hardwaretopics/storage/story/0,10801,107607,00.html

I've commented before, seemingly hundreds of times, about the insanity of photogs who'll think nothing of spending thousands on a new lens, in a fit of lust, but who rely on cheap optical media in preference to mag. tape. I currently get 500GB compressed on a single tape - and it beats the heck out of burning DVDs.

I'll leave it up to others to comment on similarities / differences between CD writable media and DVD writable media, as that's not my field.

cheers,

• kirbs

--
====================
Bring Back The Mind Of Minolta!
====================

 

[pegasus1457]

There is certainly no good reason to trust your images to CD's you paid 10¢ for, but there are CDs on the market which cost a little over $1 which are made by MAM-A and marketed by Delkin, among others.

These are gold-plated (no telltale blue dye cast) and are supposed to have lifetimes of 75 or more years.
See, for example:

http://www.photo.net/mjohnston/column53/

On the other hand, I am an "expert" on recording data on mag tape, done it for years. There have always been problems with the stability of data recorded on mag tape. One of them was print-through, where the magnetically encoded information on one layer of the tape influences information stored on the adjacent layer of the reel. The conventional wisdom practised in IT for some time was that tapes needed to be rewound from time to time to avoid having the same magnetic domains as neighbors for long periods. banks and insurance companies did it as a regular practice. I'll bet you don't do that with your 500 GB tapes!

I will keep on trusting my images to the highest-quality CDs available, until I hear that DVDs are even more reliable.

 

[jmop]

Recent results in the Netherland have shown that keeping disks in a "cool dark place" doesnt work either, infact disks left out on a desk faired better than the accepted method of storage.

Personally a pair of large external USB hard drives (mirrored) are my prefered method of storage, both go into a fire safe at night as an extra precaution + backing up to DVD.

It might well be the belt and braces approach but having suffered a complete disaster several years ago, I ain't going there again!

 

[bionet]

..because, if I remember right, it was also IBM who considered the lifespan of magnetic tapes to be 5 years a decade ago.

Anyhow, the first CD-Rs I burnt are about 10 years old now, and they still work fine. I test them every now and then out of curiosity.

 

[JKirbs]

pegasus1457 wrote:

• snip -

layer of the reel. The conventional wisdom practised in IT for some
time was that tapes needed to be rewound from time to time to avoid
having the same magnetic domains as neighbors for long periods.
banks and insurance companies did it as a regular practice. I'll
bet you don't do that with your 500 GB tapes!

Erm retension is a click away in CA Arcserve, and takes about 15 minutes on AIT-4 media. So you loose your bet, i think

I will keep on trusting my images to the highest-quality CDs
available, until I hear that DVDs are even more reliable.

I envy you your endeavor when you want a fresh archive copy or an off-site spare!

I've personally never bought the idea that CDs are either safe or practical backup. But then i've never had to yell over lost data either.

--
====================
Bring Back The Mind Of Minolta!
====================

 

[JKirbs]

..because, if I remember right, it was also IBM who considered the
lifespan of magnetic tapes to be 5 years a decade ago.
Anyhow, the first CD-Rs I burnt are about 10 years old now, and
they still work fine. I test them every now and then out of
curiosity.

I agree the story is real thin, and also i failed to find any papers by the quoted IBM'er, albeit from a very brief effort. I will say too, that if i were anybody at IBM, i'd be pretty angry at anyone talking to press without reference to substantiation.

Yes, mag. tape life can be very short too. I am presuming however that any supportive tests were carried out in ideal storage conditions. Tape dies real fast in poor storage, and so if you don't have top environmental conditioning, there for one is a cost that ups the entry price to using tape beyond what most people want to consider. My consideration is that it is far far easier to run a single tapecopy than to index and swap dozens or potentially hundreds of optical discs.

About a decade ago i'm pretty sure any research on tape life would have hit my desk. Have you any reference to jog this flu - ridden head of mine?

My own personal bugbear is the cost of time to manage big optical libraries to an archive standard. This just gets to maddening proportions when you think about modern cameras, huge 16bits per channel edits and so on. I'll trade time spent manually culling the rubbish from an archive any day for dollars on a new, bigger, tape drive. But i don't doubt at all you have 10 yr old CD-R media that is just fine. I think the IBM'er is pointing to poor quality dye substrates. Now the price for CD-R media is almost pennies, you can still pay a buck or more for some brands, per disc. (usually that means they come with pearl cases and other clutter though) so where's the money going? The article raises a very valid point - no QA measurement standards! That's bad. I keep saying it to people: one day there'll be a world shattering wail over lost memories.

--
====================
Bring Back The Mind Of Minolta!
====================

 

[jfelbab]

All media will fail in time. For me, the answer is in the back-up process. When I return from a shoot I immediately burn and verify two copies of my cards on CD's and store one in a fire safe, another in a safety deposit box. At the end of a project or at least every quarter, I archive my photos to DVD's. Three copies to three different locations, fire safe, safety deposot box and the third is sent to a relative out of state.. I keep all copies for 24 months. After 2 years I roll out the oldest as I replace the latest. This leaves me with multiple copies on multiple disks. Should I have a hard disk failure I have several back-ups available. I also buy high quality media for this back-up/archive process.

I archive my music in the same manner.

--
Jim
Listen to my music and d/l free mp3's here.
http://www.macidol.com/jamroom/bands/33/music.php

 

[JKirbs]

All media will fail in time. For me, the answer is in the back-up
process. When I return from a shoot I immediately burn and verify
two copies of my cards on CD's and store one in a fire safe,
another in a safety deposit box. At the end of a project or at
least every quarter, I archive my photos to DVD's. Three copies to
three different locations, fire safe, safety deposot box and the
third is sent to a relative out of state.. I keep all copies for
24 months. After 2 years I roll out the oldest as I replace the
latest. This leaves me with multiple copies on multiple disks.
Should I have a hard disk failure I have several back-ups
available. I also buy high quality media for this back-up/archive
process.

I think you just defined best practise.

But if one assumes (correctly) that all media will fail, there's still a need to consider recopy time and effort. Good backup software will keep a checkum for you to verify the integrity of backup, and will employ robust encoding to permit vaguaries of data erosion. This gets more complicated, naturally, when you have different storage sites, and as anyone who's managed a big disc array knows, the more copies [discs in parity array] you have, the greater the probability of individual failure. So (and i ask myself this question a lot) - which backups do you verify over time? Can the (usually) one remote stored backup be relied upon in the event of disaster? Harping on about my ongoing argument, high capacity tape is far easier to manage (even in terms of physical bulk) than numerous optical discs. Incidentally, i consider compression a no-no save for working sets that are quickly verifiable, because in long - term storage, data redundancy can be a good thing, when you get the inevitable bit rot . . .

--
====================================
Proof, it it ever were needed, that Mr. Rockwell is not a Brit
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

'This may be a blessing in disguise for fast-shooting fudge packers, since you'll start having the D200 lock up on you before you're really full, and it will free up again for another few shots.' [ http://www.kenrockwell.com/nikon/d200/d200-high-speed.htm]
= = = = = = = = = = = = = = = = = = = = = = = = =

 

[bionet]

Have you any reference

Not really, I probably read this in the German c't magazine and it was only a short note about how IBM "considers the likely lifespan of magnetic tapes no more than 5 years" or something along those lines.

I think the IBM'er is pointing to poor quality dye
substrates.

Yes, my first CDs cost between 10 and 15 DM per piece which was around $7-$10 at that time.

About the quality control, you have to do it yourself as a user of optical media. I do spot checks of the media I buy with my LG DVD-drive & KProbe, a 'leaked' LG engineering tool for Windows that can display all those values like BLER, PI sum of 8, PO etc.

That will protect against the most frequent reason for data losses with nowaday's media: a disc that was bad from the start. The only CD-Rs I have lost data with were really cheap ones that went from bad to unreadable in a couple of months. The check could be repeated in certain intervals to be sure.

Note that I have yet to lose data with even the cheapest 'fake' (wrong manufacturer ID) 1x DVD media burnt at 2x (firmware patch).

 

[pegasus1457]

My own personal bugbear is the cost of time to manage big optical
libraries to an archive standard. This just gets to maddening
proportions when you think about modern cameras, huge 16bits per
channel edits and so on.

Do you really archive anything more than the original images?

I'll trade time spent manually culling the
rubbish from an archive any day for dollars on a new, bigger, tape
drive. But i don't doubt at all you have 10 yr old CD-R media that
is just fine. I think the IBM'er is pointing to poor quality dye
substrates. Now the price for CD-R media is almost pennies, you can
still pay a buck or more for some brands, per disc. (usually that
means they come with pearl cases and other clutter though) so
where's the money going?

The $1+ disks that I buy don't come with pearls or rhinestones. That is the price per disk on a spindle.

So in principle I am paying for a higher quality product (I hope) than you are getting for $0.10

In an earlier post on this thread you said it takes 15 minutes to retension your tape. But that didn't include the time to visit your safe deposit box or fireproof safe (twice - once to retrieve the atpe, once to replace it).

My point is that I don't believe you do this for all of your tapes once you have a bunch. Do you really?

 

[Malcolm Turner]

Years back, I was involved with backup systems for the computer systems on our customer sites. Every new computer system had a different tape drive with a different cartridge format. I know this has standardized nowadays, but tape alwaysseemed to be inherently unreliable, and I was very glad when we moved to Oracle databases that can recover from an older backup and rebuild the data from archive logs.

CDs are at least standard, and future systems will still be able to read today's CDs and DVDs.

My understanding is that DVDs are inherently less stable than CDs - hence the different location method in standard DVD cases to avoid flexing of the layers, which some computer magazines point at as the cause of degradation.

As one of the other posters said, I backup up the shots I don't want to lose on 2 sets of CDs and periodically also burn to DVD.

These are so cheap - here in the UK I can get branded CDs for about 40p each in a case, and DVDs for about 80p. Not a lot to pay.

 

[insectman]

will store your cherished images virtually forever ... it's magnetic ... i.e. the good old hard disk! O K so your hard disk fails ... but for a couple of hundred bucks/pounds you can get all of your files back ... because its the mechanics of the drive that eventually fail ... not the layers of disks that you store your images on. Cd-r disks are an unknown quantity, cd-rw disks are known to be non-archival ...... the jury is still out on out DVD disks. My opinion is that if you store your files on magnetically-recorded media then, like Adolf Hitler's rantings from the 1930s..... they will be there forever!

 

[Reinhard #50659]

Hmm. Tape based backup.

http://www.backuptrauma.com/



--
--Reinhard

 

[JKirbs]

Hi,

Do you really archive anything more than the original images?

Yes, absolutely. There may be hours, even hundreds of hours work in optimising a image for a specific press or output. That won't change until there's some kind of OPI that works with RAW, not that meta - edit lists ever were interchangeable anyhow with scans, or anything for that matter.

I'll trade time spent manually culling the
rubbish from an archive any day for dollars on a new, bigger, tape
drive. But i don't doubt at all you have 10 yr old CD-R media that
is just fine. I think the IBM'er is pointing to poor quality dye
substrates. Now the price for CD-R media is almost pennies, you can
still pay a buck or more for some brands, per disc. (usually that
means they come with pearl cases and other clutter though) so
where's the money going?

The $1+ disks that I buy don't come with pearls or rhinestones.
That is the price per disk on a spindle.
So in principle I am paying for a higher quality product (I hope)
than you are getting for $0.10

I never said anything about my buying media for ten cents. It was illustrative, as should be evidenced by my obvious aversion to optical archive.

In an earlier post on this thread you said it takes 15 minutes to
retension your tape. But that didn't include the time to visit your
safe deposit box or fireproof safe (twice - once to retrieve the
atpe, once to replace it).

Erm, and i raised that point above, in the context that rather i would pull a single tape from storage than a box of optical discs (or many small capacity tapes). Couriers or a decent storage company solve the drive - time issue

My point is that I don't believe you do this for all of your tapes
once you have a bunch. Do you really?

Yes, if i read your question right (ambiguous). That's a major reason why i moved to the highest density tape i could get at a reasonable price. I still store 20GB DATs, but the data migrated, because of the huge hassle of managing and securing many many tapes. I would be using S-AIT, if it were'nt for the format incompatibility. Sony delivered very well on their roadmap for AIT. Compliment not astroturf.

--
====================================
Proof, it it ever were needed, that Mr. Rockwell is not a Brit
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

'This may be a blessing in disguise for fast-shooting fudge packers, since you'll start having the D200 lock up on you before you're really full, and it will free up again for another few shots.' [ http://www.kenrockwell.com/nikon/d200/d200-high-speed.htm]
= = = = = = = = = = = = = = = = =t = = = = = = = =

 

[JKirbs]

Hmm. Tape based backup.

http://www.backuptrauma.com/



--
--Reinhard

Cool, thanks for the advert! From a company, no less, that just takes the hassle away for a fee. No disrespect to John Cleese, incidentally.

 

[Reinhard #50659]

Totally true.

I only posted this for the hilarious ad
--
--Reinhard

 

[Jay Turberville]

..because, if I remember right, it was also IBM who considered the
lifespan of magnetic tapes to be 5 years a decade ago.
Anyhow, the first CD-Rs I burnt are about 10 years old now, and
they still work fine. I test them every now and then out of
curiosity.

Yep. Just last week I restored a project (animation/video) from a CD-R that was burned in 1997. it was about 8 1/2 years old. No problems.

Well, that isn't quite true. We have lost data on a CD in one instance and in one rather unpredictable way. We had some double disc cases where the center hub gripped the disc with such force that that it started crack propogation from the disc's center hole. Very odd and I've never read of anything like it. So we purged our archives of those cases (finding many discs with cracks beginning, so we just duped those discs).

My own personal bugbear is the cost of time to manage big optical
libraries to an archive standard.

That is interesting. We went to CD-R because it was so much more convenient and easy to manage. No maintaining records of what a tape contained. No need to restore the tape to verify the contents. Just pop the disc in a drive and read it directly using standard tools on any machine. Drag and drop restoral of folders using standard OS tools is very convenient. We just make a disk "package" for each project and file by project. Simple and quick.

But i don't doubt at all you have 10 yr old CD-R media that
is just fine. I think the IBM'er is pointing to poor quality dye
substrates.

Ummm - no. "Gerecke said. "Some of the better-quality discs offer a longer life span, of a maximum of five years." Didn't you read the article?

The article raises a very valid point - no
QA measurement standards! That's bad. I keep saying it to people:
one day there'll be a world shattering wail over lost memories.

I searched the text. The word "standard" or "standards" is never mentioned. Neither is the term "QA" or the phrase "quality assurance". What article are you referencing?

As for lost memories, my wife is currently scanning her fading color photos . If I end up duping my CD-Rs to DVD and then later to Blue-Ray or some higher capacity optical disc in the future, what's the difference?

--
Jay Turberville
http://www.jayandwanda.com

 

[pegasus1457]

NT => no text, Phil

 

[JKirbs]

But i don't doubt at all you have 10 yr old CD-R media that
is just fine. I think the IBM'er is pointing to poor quality dye
substrates.

Ummm - no. "Gerecke said. "Some of the better-quality discs offer
a longer life span, of a maximum of five years." Didn't you read
the article?

I merely wasn't doubting the personal report. Unconnnected comment with the article.

The article raises a very valid point - no
QA measurement standards! That's bad. I keep saying it to people:
one day there'll be a world shattering wail over lost memories.

I searched the text. The word "standard" or "standards" is never
mentioned. Neither is the term "QA" or the phrase "quality
assurance". What article are you referencing?

Well, i read the article, and it was very short on explaining itself, leaving me to infer what the quoted IBM guy was hinting at. I think you failed to comprehend what i wrote, and that a point can be raised by implication. You've read my post as literal grammar, incorrectly.

As for lost memories, my wife is currently scanning her fading
color photos . If I end up duping my CD-Rs to DVD and then later
to Blue-Ray or some higher capacity optical disc in the future,
what's the difference?

This isn't a sequitur in your argument. I've made my points above.

--
====================================
Proof, it it ever were needed, that Mr. Rockwell is not a Brit
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

'This may be a blessing in disguise for fast-shooting fudge packers, since you'll start having the D200 lock up on you before you're really full, and it will free up again for another few shots.' [ http://www.kenrockwell.com/nikon/d200/d200-high-speed.htm]
= = = = = = = = = = = = = = = = = = = = = = = = =

 

[JKirbs]

My own personal bugbear is the cost of time to manage big optical
libraries to an archive standard.

That is interesting. We went to CD-R because it was so much more
convenient and easy to manage. No maintaining records of what a
tape contained. No need to restore the tape to verify the
contents. Just pop the disc in a drive and read it directly using
standard tools on any machine. Drag and drop restoral of folders
using standard OS tools is very convenient. We just make a disk
"package" for each project and file by project. Simple and quick.

I think you're writing as if i was some kind of nutcase, or at least deliberately with a hint of sarcasm, as if to imply i am de facto wrong.

When CD-R first came out, there were plenty of issues IIRC with quality of burning software / buffers / throughput & buffer problems that could lead your disc to end up a coaster. I know we don't suffer this any more, but a poster above mentioned problems with blank media. I don't use enough of the stuff to comment on that.

FYI i do not need to load a tape to idex it or search file metadata - that information exists in a (separately backed up) database created by Arscserve (similarly for other backup apps) and if i want to i can expose this to the OS by setting backed-up volumes as remote media.

Also FYI i do not need to restore to verify, if i maintained checksums in the database. Depending on the granularity of these, it can be a longer operation, granted.

I really don't see how any of your operation is easier than leaving a system set to twice daily incremental backups, and weekly full backup, running in the background. I prefer zero user intervention, where it concerns anything that's a important procedural decision.

There's also, IMO, a handling risk involved with optical, if you accidentally scratch the disc, and in pulling individual discs, greater manual organisation. Certainly i'm not arguing your system is inadequate, but other considerations may be more important. For example, i don't like drag and drop because (on NT thru XP) the creation date is altered, leaving you with only the modified date to indicate the date origin, which will be invalid if any file sees another edit.

The final killer is your data creation rate. If you deal with pre - press, or even just avidly shoot a current > 10MP camera and don't want to cull images by hand or unused shots you may repurpose (e.g. brackets you might later wish to merge to HDR) it's not impossible to generate GBs worth per day. If you have low volume data, then fine, you may well find opticals far easier. If you use non - "industrial strength" backup software, you may not be able to manage a tape archive effectively at all, period. But my view is that with a full TB coming to a desktop soon, even BD and HD DVD writables may be insufficient. Tape is already "there" or at least nearly there, in terms of capacity. Other benefits may accrue as well, such as the ability to do large bare - metal restores if you have a disaster, which is important to business continuity.

You say you "went to CD-R". Did you use tape before that? Not all tape is created equal, and certainly there are some tape systems i would have strong opinions about, technologically, even before considering other factors. Basically, i think the options simply got a lot better in recent years, and the price premiums diminished substantially, too.

best from me,

• kirbs

--
====================================
Proof, it it ever were needed, that Mr. Rockwell is not a Brit
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

'This may be a blessing in disguise for fast-shooting fudge packers, since you'll start having the D200 lock up on you before you're really full, and it will free up again for another few shots.' [ http://www.kenrockwell.com/nikon/d200/d200-high-speed.htm]
= = = = = = = = = = = = = = = = = = = = = = = = =