For adding extra redundancy information, you may like to look into the
PAR2 format. For CD or DVD images (.iso) look at the program
'dvdisaster'. Each method has its own advantages.
Here are some posts comparing the options with implementation details as
George Brock-Nannestad wrote:
> From: Patent Tactics, George Brock-Nannestad
> Steve Smolian asked whether CD-Rs or DVD-Rs had the longer lifetime. This
> permits a different approach. If one really considers that one could settle
> for a storage capacity of a CD, then the much larger storage capacity of the
> DVD (8+ GB in two-layer) may be used for redundancy. Repeat the 700 MB over
> and over again is a primitive way, but it would permit retrieval of data,
> even if a radius range were splotched. More intelligent ways would probably
> permit a compromise, so that perhaps would go into 2 GB safely per DVD-R.
> Kind regards,
> --who believes that even gardeners go on strike sometimes
>> On Tuesday, June 30, 2009 11:30 AM, Steven Smolian wrote:
>>> Is there a reliable recordable DVD for long term storage,
>>> independently tested?
>>> How does this compare with the anticipated lifespan of
>>> gold-reflective CDs?
>> On the near horizon there may be a new family of optical
>> media that is mechanically etched directly into the media
>> rather than "burned" into an organic dye.
>> These new optical discs will require a special "etcher",
>> but the etched disc will be playable in a standard CD,
>> DVD or even Blu-Ray player.
>> Estimated life spans could be on the order of millennia (far
>> outliving the devices used to read the discs).
>> I've heard from the manufacturer that they can etch a disc,
>> place it in an autoclave (at temperatures high enough to
>> curl a normal polycarbonate CD or DVD), remove the etched
>> disc from the autoclave, let the disc cool, and then read
>> it without difficulty.
>> I hear these new "etched" optical discs are going into
>> beta test (blanks and etchers) later this year at a handful
>> of select sites. I hope to visit their manufacturing plant
>> later this summer.
>> If you need something equally archival right now, I've had
>> chemically etched glass CDs (using a photolithographic
>> process) produced for my clients. These are not inexpensive,
>> on the order of 10-15x the cost of a MAM-A disc. Aside from
>> the fragility of glass, these chemically etched glass discs
>> probably have lifespans on the order of millennia. If the
>> reflective layer ever fails, you simply recoat the disc.
>> There are no layers to delaminate. And they are highly
>> scratch resistant. Of course, once again the media will
>> outlive the equipment to read the media.
>> Eric Jacobs
>> The Audio Archive, Inc.
>> tel: 408.221.2128
>> fax: 408.549.9867
>> mailto:[log in to unmask]
>> Disc and Tape Audio Transfer Services and Preservation Consulting