After posting the Photo Backup: DVD and Photo Backup on DVD: Love or Hate articles, we had a lot of reader comments and discussion about this medium. I realize many of the readers don't check on the comments section days or weeks after the article is published, so I wanted to follow up the two articles with some new thoughts and insights on DVD backups.
I would also encourage you to read through the comments in each of these articles. They are filled with stories on both sides of the line — users who have had nothing but problems with DVDs, and those who use them currently.
INTEGRITY OF DATA
The problem with any digital storage media is that it has a relatively short lifespan. Hard drives and DVDs alike, won't last forever. DVDs seem to have a wide range of results when it comes to data integrity. You could potentially burn a disc and have the data be bad right from the start. Or you could burn a good copy and have the data go bad after a very short time (on the order of a year or two). You could also have discs that are 10 years old and still working fine.
The point is that you shouldn't expect DVDs (or any other storage media) to last forever. Construction, quality, materials, formats, process, handling, storage, and temperature all have an effect on the integrity of your data. I'll cover a few tips on ensuring good data at the end of this article.
DVD FORMAT WARS
Several people brought up some good points about the various DVD formats. I had stated that the “R” (record once) discs are best to use because they're inexpensive and you won't run the risk of overwriting data.
It turns out that “R” discs are less archival than other formats due to their construction. These “R” discs use an organic dye that reacts with the laser. The dye can break down over time and cause data to be lost.
The “RW” discs, on the other hand, use a metal alloy as the recording medium rather than an organic dye. The material is more robust and it gives the disc a better chance of retaining data over longer periods of time.
The “RAM” discs are also good candidates for archiving photos. Their construction is similar to the “RW” discs (metal alloy rather than a dye) and they have built-in error control and a defect management system (don't ask me how though).
TIPS FOR DVD BACKUPS
Regardless of which format you decide to use, there are a few things you can do to increase the life expectancy of your DVD backups.
- BUY HIGH QUALITY DISCS
Like many things out there, you get what you pay for. Higher priced discs generally have better construction than the bargain discs. I personally use Sony discs, and I've never had a problem with them in over 5 years of use.
- BURN AT LESS THAN FULL SPEED
I don't know if this one is myth or fact, but I've always burned at half of the fastest setting on the drive and/or media. I've heard that writing at super-speed can give you a poor burn, but I don't know how much truth there is to this. I typically use 8X for my DVDs even though my drive and discs are capable of 16X.
- STORE DISCS PROPERLY
Once you burn the disc, put it away and leave it alone. Get a sleeve book or use jewel cases — you don't want your discs sliding around and getting scratched up. Also be sure to store them in a relatively cool dry place. Heat and humidity accelerate the aging process on most materials.
- REPLACE OLDER DISCS
If you aren't using archive quality discs, you might consider replacing old ones after five years (which is why it's good to indicate the burn date on the disc). If you're really confident or if you want to risk it, you might be able to push it out to ten years. RW and RAM discs might last a bit longer, but I'd still replace these after around ten years. Regardless, it's a good idea to check on your older discs every few months to see if everything is still there.
- DON'T USE AS YOUR ONLY BACKUP
No matter what you're using for a backup solution, only having one backup is risky. I would suggest to keep at least two backups, one of which should be off-site. I use DVDs as my secondary backup and I keep them off-site. My primary is an external hard drive that I keep in a fireproof safe on-site.
What other tips or suggestions do you have for backing up on DVD? And I promise, this is the last one on DVD backups.