CDs and DVDs have become means for storing your data. They offer an easy way to transfer data and also serve as a suitable medium for data back-up. They primarily work on the same basic principle consisting of certain manipulations on a particular layer present in them which are later ‘read’ by means of an optical laser. Rewritable versions of CDs and DVDs are also available which work on a slightly similar principle.
The Basics
The lower part of the disc is made up of a polycarbonate plastic which is important for focussing the light from the laser on the required surface. This surface is therefore important and is also susceptible to frequent damage. The various problems that can be caused to the plastic layer are disfiguration of the surface or turning yellow, change in shape or warping of the disc on exposure to heat and the most common problem of scratches on the surface which is not always a serious problem but may prove to be so depending on the severity of the scratches. Other problems faced while using them are scratches on the top side of the disc which may lead to actual data loss; delaminating of the layers can also occur in certain conditions which will make the disc obsolete. But even when such unavoidable problems are taken into consideration, CDs and DVDs of a good quality have a life span of almost 300 years. Even the ones of a moderate quality can last for 50 years.
Thus even if there are chances of data loss from a CD or DVD which makes the data irrecoverable, with proper care, they can act as quite efficient means for storage of data over long periods of time. Also nowadays various software have been developed which claim to be able to recover data from damaged and scratched discs but the authenticity of the same in all possible scenarios has not been confirmed yet.
Measures to Protect Your CD or DVD
- Exposure of the discs to high temperatures should be avoided. Such an exposure is likely to cause warping or delaminating. Also in rewritable discs, actual data loss due to damage to dyes is possible.
- Humid conditions are also to be avoided as they may lead to oxidation of the reflective layer and thus cause discolouration which leads to inability of the laser to read the data.
- Frequent changes in temperature and humidity will also cause physical damage to the discs and should be avoided.
- Discolouration of the polycarbonate plastic layer takes place due to exposure to intense sunlight, Ultra Violet light etc. As a protection from this, CDs and DVDs should always be kept in the proper cases provided for the very purpose when not in use. The cases are useful as they avoid any contact of the lower surface with other objects.
- See to it that the case is such that it has a central support.
- The cases used to store the discs during travel are usually made of fabric materials and are suitable for short term storage only.
- While handling the discs, hold those by their edges and the centre hole, as finger prints on the lower surface may cause difficulty for the laser while reading the data.
- Avoid scratches especially on the upper surface.
- Do not place heavy objects over the disk and store them upright whenever possible.
- While writing on the disc label, it is preferable to use a pen that has been especially provided for the purpose as some of the other pens are known to cause chemical reactions. Adhesive labels are a good idea. However at times they tend to peel off when used in the type of players generally found in cars in which you slide the discs in.
- Keeping the discs clean from dust is also a good idea to avoid scratches; the cleaning should be done using a soft cloth or a brush.
CDs and DVDs as Data Backup Media
The major concerns while backing up the data are the durability of the medium used and availability of storage space. These discs are quite durable if handled with care and also offer an amount of memory (700 Mb for a CD and for a DVD even up to 18 GB depending on type) which proves to be ample in most cases.
They are highly reliable and require only a few precautionary steps to protect them against damages. So be proactive and be benefited by various advantages offered by these storage media. Data Recovery is available for back up media.