This is an ancillary post regarding lifespan of a DVD:
Quoting from National Archives FAQ on Optical media storage:
5) What is the shelf life of unrecorded CD-R/DVD-R discs?
It is best to purchase new CDs/DVDs as they are needed. According to the Optical Storage Technology Association (OSTA), the unrecorded shelf life of a CD-R/DVD-R disc is conservatively estimated to be between 5 and 10 years. Source: http://www.osta.org/technology/cdqa13.htm
6) How long can I expect my recorded CDs/DVDs to last?
CD/DVD experiential life expectancy is 2 to 5 years even though published life expectancies are often cited as 10 years, 25 years, or longer. However, a variety of factors discussed in the sources cited in FAQ 15, below, may result in a much shorter life span for CDs/DVDs. Life expectancies are statistically based; any specific medium may experience a critical failure before its life expectancy is reached. Additionally, the quality of your storage environment may increase or decrease the life expectancy of the media. We recommend testing your media at least every two years to assure your records are still readable.
11) How should I handle CDs and DVDs?
Handle discs only by the outer edge or the center hole, never by touching the surface. Fingerprints can disrupt the tracking of the laser on the disc. Follow the manufacturer's instructions to remove any dirt, fingerprints, or smudges.
13) How do I store the discs to extend their useful life?
Discs are best stored upright (like a book) in "jewel" cases that are designed specifically for CDs/DVDs. Ideally, store the cases in plastic or steel containers manufactured specifically for the type of medium in cool, dry storage that is free of large temperature fluctuations. Generally, useful life will be increased by storing discs at a
low temperature and low relative humidity, since chemical degradation is reduced in these conditions. Store at 62-70 degrees F. and 35-50% relative humidity. Fluctuations in the storage area should not exceed +/- 2 degrees F. in temperature; relative humidity should not fluctuate more than +/- 5%.
Additional data are here in an excellent experimental report by J.Iraci: "Relative Stabilities of Optical Disk Formats," Joe Iraci, in the Restaurator - International Journal for the Preservation of Library and Archival Material (2005) (http://www.uni-muenster.de/Forum-Bestandserhaltung/downloads/iraci.pdf).