It is quite a suitable technology for data backup.
CDs come in two varieties viz. ones that are rewritable and the ones that are not. The rewritable ones are quite convenient for data that needs to be backed up for limited periods of time.
They are portable and easy to use and store (the storage requires a few precautions though if storage is intended for longer periods of time).
They are especially suitable when small amounts of data are to be stored (up to 700 MB).
Cons
Backing up of data on a CD requires a CD writer which is not installed by default in all computers.
Regular usage or mishandling of a CD will damage it beyond recovery after some time.
DVDs
Pros
The DVDs are preferable because of their large amount of storage space they offer (up to 21 GB)
Also they offer high data transfer rates ranging from 3.96 MB per second to 21.13 MB per second.
They are portable, inexpensive and have a large life span.
Cons
A DVD burner which is necessary to burn data onto a DVD is a bit expensive and hence adds to your initial investment.
They also become unreadable when not handed with care.
Pen Drives or Flash Drives
Pros
They can hold data up to 4 GB and hence suitable for storage of large amount of data.
Transfer rates are very high (48 MB per second for USB 2.0) when compared to CDs or DVDs.
They are highly durable and can be transported very easily. Also as they fit into the USB ports which all computers have, they can function on all computers.
Cons
They are quite expensive and so for backup of very high volume of data, they can prove to be quite an investment.
They can be misplaced easily as they are small in size.
Tape Drives
Pros
They have a very high capacity for storage (up to 100 GB).
Cons
They are very expensive.
They need to be administered.
Portable Hard Drives
Pros
They offer the largest storage capacity among the ones mentioned. Some of them can even store data in excess of 250 GB. Hence they are quite suitable for backup of large amounts of data.
These as well make use of the USB technology and hence offer high transfer speeds and easy installation as well.
y can also hold data for quite a long time (up to 15 years).
Cons
They prove to be quite expensive.
External magnetic fields can have adverse effects on them.
They need careful handling and will get damaged if dropped etcetera.
Choice of Media ? The Last Word
All of the media mentioned above have some advantages and some disadvantages. So choice among them can be quite difficult. To choose the best among them, you need to analyse and clearly determine your requirements. To help you in this process, see how much of data do you need to back up, also for how long the data should be retained, the portability of the media and finally the amount of money you are willing to invest in the same.
Also some media such as the portable hard drives or the pen drives offer you large amount of manoeuvrability with infinite number of rewrites so they are generally preferred over CDs.
Thus, remember to make your choice wisely and never ignore the backing up of data as you may never know as to when a disaster might strike you. Also backing up relieves you from the tedious process of data recovery which also can be expensive.
