How long do optical discs last? How long will your old CDs or DVDs keep the information? There is no concrete answer, but we do know that it is time to check if they have withstood the test of time before it is too late.
If you have been in computing for a long time and had your time – as the signature of this entry – of ‘compulsive buyer and downloader’ it is likely that you have a large number of old optical discs with all kinds of content. These were times when only a few privileged people had access to the Internet and we saw the cloud in the sky as masses of ice and water crystals. Hard drives were quite expensive and their capacity was limited, while systems like NAS were limited to the business environment.
In that scenario, and once we left the floppy era behind, optical discs, first CDs and then DVDs, were a blessing and became tremendously popular. Although they were not cheap in the beginning, when consumer units capable of recording and then re-recording reached the market, the explosion of use was definitive and they became the main external storage medium.
How long do optical discs last?
It is likely that you have gone through the commented stage and have a large number of units that you use little or nothing. And stored God knows where and in what kind of conditions, because not all of us kept them conveniently in their box and there were plenty of batteries of 50 or 100 units where the discs went one on top of the other. If you think you have relevant information stored (you never know what might come out of a record recorded 20 years ago), music collections or other content on compact discs, it’s time to get down to the job of saving before it’s too late.
An exact figure for the longevity that optical discs can achieve is not known. A few years ago the Canadian government published a study on the subject that, although technically quite complete, did little to answer the question since it concluded with a very wide arc: from 2 to 200 years of life.
Much of it will depend on the initial manufacturing quality. Production in the years of maximum use was huge to meet demand and lower prices and surely the majority of units that came to market were not of the best quality and chemical degradation has been able to accelerate between the different layers that make up the optical discs. . In fact, in the study the shelf life varies greatly depending on the brand used.
Layers of a DVD
The same recording unit used and the speed at which it was recorded (the lower the better) is also another section that intervenes, as well as the subsequent handling to avoid physical damage such as typical scratches. Also the same stored to reduce the problems caused by ultraviolet light, reactions to contaminants, disunion of the adhesive layers of the disc and oxidation of the reflector. Temperature, humidity … everything influences.
The Canadian study is curious to catch up, and there is a similar one also interesting from the Library of Congress of the United States that reaches similar conclusions: it is not possible to determine the useful life of a disk, but sooner or later the information will be lost or it will become unreadable on a conventional reader.
How to make copies of optical discs?
Manual copy. The simplest way to back up old data on a disk is to transfer the content to a hard drive, solid state drive, flash drive, NAS, or cloud storage from the same file browser. This manual copy can be done from any operating system by creating separate folders on the destination drive for better organization.
Disc images. There are times when you will find a correct status disk, but it cannot be read in the operating system you use because it does not have compatibility. For these occasions, disk images are ideal as they can copy the structure of an optical disk, including all file data and the file system (if any), so that it can later be replicated to another disk new if you ever want to use it. There are good applications to do it as we saw in this practical article.
Capacity. The capacity needs to make backup copies will vary enormously depending on the user and the number of drives to handle, considering that a typical CD occupies 700 MB and a DVD ranges from 4 to 17 GB. We would leave Blu-ray aside for its tremendous capacity and – we suppose – that it must still be in good condition as it is newer. Personally, I cleaned up a long time ago and used hard drives that I had removed from PCs by replacing them with SSDs, cloning of collectible music discs and uploading to the cloud of the professional files that appeared.
Readers. The slump in the use of CDs and DVDs amid the general decline in physical formats for content distribution has put optical disc players on the brink of extinction and most new equipment no longer includes them. Fortunately, external players / recorders are priced, can be purchased for less than 20 euros and work on any computer’s USB ports.
What if the disk has errors? If you have discs burned 10, 15, 20 years ago, you are likely to encounter errors on some drives. Depending on your grade there are several ways to act. The first is to try other readers, because it is not uncommon for one to be able to read it and others not. Then we would copy all the data that we can save. For the rest, we can use data recovery software like IsoBuster. It works in the same way that we saw to recover files from a PC.
Beyond there we cannot reach. If the data is incredibly important and irreplaceable, you can hire a professional (very expensive) forensic data recovery service to extract what’s left of it. Or what they can, because if they have physical damage to the lower layers it may be that there is nothing to do. Not even using the trick of toothpaste that does not go beyond a thorough cleaning, mandatory on optical discs, as well as the care in its handling and storage as protected as possible.
In the end, it is a medium that will end up degrading. If you have stacks of accumulated optical discs, it is best to get down to the task of saving important ones before it is too late.