I sorry to say that HDD backup never safe. I suart , Due to flood arround 50,000 computer sunk. Around 90 % copmputer start again But 100 % hdd loss No one get data of hdd. Who have take backup on cd or dvd 100 % safesydras said:I know the attraction of a dual layer - i.e to store more data so that you have to keep a lesser no of discs lying around. This problem of storage has plagued us fellas from the days of floppies. If you're looking for storage, nothing beats hard drives. Flash/Optical/Magneto-optical/Zip drive/Orb drives nothing can compare to the ease and capacity of hard drives.
I recommend the foll. based on your requirement.
1)
If it's cost that is your main impediment, then you will have to keep using single layer DVDs. The advantage optical media have over magnetic media is that they are reliable if you take care of them. The disadvantage is slow reading and irritating sequential writing(random write packet writing softwares are just plain unreliable - I once lost all my data on such a floppy CD). Plus due to limited space, you will have to keep a box or two lying around.
2) If you have some cash, say around 5000 bucks and a lot of data to store, go for a 7200 r.p.m, 3.5 inch, 300 GB HDD and enclose it in a HDD USB casing that retails for around 800 bucks(Rs 2,000/- for firewire cum USB casing but you need a firewire port also on your PC). You will enjoy the ease of use of such a setup. Just be careful with the drive and don't treat this drive as a final resting place for your data. When you get some extra cash, go for another HDD and back up your backup to be safe.
3)
If you have around 7,000, go for a 5400 r.p.m, 100-120 GB, 2.5 inch laptop HDD in USB casing. You will love the fact that it does not need a power cable and can be driven by the USB data cable only(USB is a powered interface). As always with magnetic media, when the prices of HDDs come down, please get another HDD to back up your backup. Or at least, backup your critical data or the stuff you will never modify on DVDs. This will help you sleep safe at night
Hope this helps.