Best CD or DVD Recordable Media for Longevity?

icepick72 asks: "I have recently purchased a collection of music (on CDs) for a music group that had their final tour last month. Without getting into copyright issues (I'm writing from Canada -- not that it necessarily makes a difference) I would like to know if any CD-R media on the market supports longevity. In the past Slashdot has discussed the degradation of CD/DVD media. How do I go about knowing what the good media is nowadays, and how to get a decent price on it? One company uses this foil or that foil while another uses polywatchmacallit. Looking for good suggestions, and an archived discussion on Slashdot for future reference."

Comments

Try this:

[dcapel]

rippify to a nice open codec that won't lock you out, then upload to gmail. My bet is its totally safe for years and years to come...

ZipLock Freezer bags, Quart size

[Futurepower(R)]

Basically, you want the surroundings to be chemically inert. We always put all our DVDs and CDs in ZipLock Freezer bags, Quart size. The package says they have a "FreezeGuard Seal", which means that you can expect that all moisture is excluded.

Freezer bags have extra thick plastic, which provides good, slippery, mechanical protection, too.

If you expect to store the DVDs and CDs for a long time, put the Quart size bags inside Gallon size Freezer bags.

For extreme protection, go to a shoe store and ask them for those little packets of dessicant (moisture remover) that are in each box of shoes. They'll give them to you free. Put one in each Gallon bag. I don't put them in the inner bag because the impurities in the dessicant granules might be abrasive.

Parity (.par) files for extra safety.

[WoTG]

For photos, backups and other archival stuff to CD or DVD I've been adding PAR parity files. They're sort-of like RAID at a file level. Even though the initial use of .pars was for Usenet binary downloads (I think) the tools work great for any situation where partial loss of data is likely. In theory, as long as the unreadable bits of the disc are a small % of the disk, I should be able to rebuild the data. There's an article where this is tested by scratching / drawing on a CDR -- unfortunately, I don't have a bookmark. The chances are good that a disk will not go bad uniformly across the entire disk. So, the parity files should be able to recover from most scratches and a lot of bit rot.

Plus, I feel that .par files are better than making 2 copies of the same data. For example, if you're only backing up a few large files, the odds of having both copies of the file get a few bad sectors is relatively high. I suppose you could patch over unreadable bits with a hex editor or something, but I'll take a nice GUI and relatively common software anyday.

Although, to be perfectly honest, I just don't rely on CDR or DVDR. I keep a copy of all stuff on a hard drive too. DVD's go offsite, HD stays at home.

Use Metal, not organic-dye, IOW, use DVD/CD-RW

[NOPteron]

Use RE-Writables, not WORM.

RW discs:
*blanking aneals metal-layer in disc
*burning quick-melts spots of metal in disc, so they freeze quickly to different crystallization than the annealed "normal"
*reading means reading the changes in reflectivity that occur ( or differences in polarization, in magneto-optical, IIRC ) in the METAL reflecting the laser-beam.

Write Once discs:
*new disc is "blank"
*laser "burns" organic-dye in writing,
*reading-laser "sees" the diff between burnt and non-burnt as less-transparent vs more-transparent, and the reflective-layer behind-it means that this is usable binary encoding. . . ( beam goes through organic-dye twice and then is read, or perhaps gets-eaten by the burnt dye and then its absence is read. . . )
*organic-dye decays

IF you care about archival, you then store complete versions of your files,
with checksums and ECC on RW discs.

IF you are using organic-dye write-once discs, then you are basing your ability-to-recover your stuff based on Estimates & Marketing Claims(tm). ..

Cheerses