Efficient Optical Disks Backups

2013.01.09

Optical disks, be it CD, DVD or Blu-Ray, make an excellent choice for digital backups. Disks are quite cheap and most importantly highly reliable. Once burned correctly, a quality disk will last for years. It can also take a good amount of abuse before becoming unusable, something that traditional hard-disk drives (HDD) cannot.

Since each disk has little value and is separate from the device to record them, optical disks are unlikely to be stolen and can be easily distributed between multiple locations, making replication and distribution of backups very simple.

There are several downsides to optical disks. Burning is slow and the process has a bad reputation of being unreliable. In this post, you will learn how to overcome these issues so that you can take advantage of this excellent medium.

Each disk takes time to burn, between a minute for a CD to over an hour for a Blu-Ray. Nothing can be done about this but the number of disk burned can be optimized:

• Pick the right disk size. A CD holds around 700 MB, a DVD 4.5 GB and a single layer Blu-Ray 24 GB. Other smaller and larger formats exist but these are the most common. Choose a size that matches your needs, at least greater than the amount of new data you generate in a week, prefer. The image above shows a stack of DVDs and Blu-Ray disks with the same amount of data. Which one would you rather have?
• Organize your media. Images and videos are unlike other data. They get created and stay the same for the better part of forever. This means that you do not have to keep burning the same images over and over. So, make sure your source files are organized in a way that makes it easy to know what is already burned and what is not. Keep one folder per disk. Once a folder reaches capacity, it should be made read-only and burned to a disk of the right size. A new folder is then created for the next disk.
• Reburn ever 5 to 10 years. Eventually, the pile of backup optical disks get too big. That is the time to change types of disk. If you used DVDs before, you can move to Blu-Ray. This requires some reorganization on disk but is good because it keeps your data fresh. Even quality optical disks degrade and by copying the old data into new disks, the likelihood of corruption greatly decreases.

The burning process is notoriously accident prone and often creates coasters. These disks end up costing money and, more importantly, wasting your time. There are three things that can improve your odds of creating a perfect disk:

• A good burner: Burners range from incredibly cheap to costly and their performance varies accordingly. Plextor, NEC and Pioneer produce the best burners on the market. While Plextor drives are rather expensive, ones from Pioneer and NEC are not so much. If your burner's brand starts with L and ends in G, chances are you burn plenty of coasters. There are other good and bad brands, check the reviews and remember that you get what you pay for!
• Good media: Archival quality media lasts the longest and is the most reliable. It costs a tiny amount more per disk but this is definitely not the place to skimp. Also, not all burners like all media equally. Most manufacturers provide a compatibility list of media they tested with their burners. Get good ones from that list. Right now with the Pionner and Plextor burners here, Verbatim and TDK prove the most reliable.
• Burn Carefully: Luckily the days of IDE burners are gone. Anything that used your disk ran a high risk of cutting the flow of data to your burner and produce a dreaded coaster. With modern SATA drives this is no longer true but a drive still needs data to burn in a continuous stream. For this reason, it is unwise to burn an optical disk while taxing the system. Burn from AC power if using a laptop to avoid it going to sleep partway through. The easiest is to leave the computer while it burns a disk at night or during meals.

Regardless of how careful you are, it is still possible that an error will create a coaster. This is increasingly rare with DVDs but not so much with Blu-Ray which is a relatively technology. So, before committing a disk to storage, verify its integrity. For the extra paranoid, burn everything twice using different brands of disks. That way, the chances of data loss are greatly reduced. Note that they are never zero! The more effort you put in your backups, the lesser the chances but there always remains the possibility that data will be lost.

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