Inexpensive Long-term (10-20-year) Archival Storage

Question

Historically, optical media appears to have been the best choice for inexpensive 10-20 year storage, but over the years, optical storage just hasn't kept up:

• CD-R was introduced around 1988 with 600-750MB of storage when typical computer hard drives were around 30MB (20x hard drive storage)
• DVD-R was introduced around 1997 with 4.7-9GB of storage when typical computer hard drives were around 5GB (1x hard drive storage)
• BD-R was introduced around 2006 with 25-50GB of storage when typical computer hard drives were around 300GB (1/6 hard drive storage)

What is the most inexpensive option for 10-20 year data archival?

Requirements:

1. reasonably reliable (maybe 95%) after at least 10 years in typical home storage (on a shelf with temperatures around 70 degrees F +/- 20 degrees)
2. have a reasonable capacity of at least 500GB
3. cost less than HDD, and
4. be a technology that is likely to still be around in 10 years (no single-manufacturer devices unless they are so popular that working used devices are likely to be available and usable in at least 10 years, like Iomega Zip drives were)

Answer 1

Your criteria are impossible to merge together and here is why, ordered by cost.

1. You need a 10 year reliable storage that can handle more or less industrial quality requirements.

   This is a quite high requirement. Industrial quality is gained by using better materials/components and so have an higher cost.

2. You need a technology that is still around 10 years later. This one is also quite difficult to obtain. As you say: you must use only very popular method of archiving witch exclude almost every archiving technology (even tape) because they evolve and, in a 10 year timespan, are not backward compatible.

Those two points come against a cheap method of archiving.

Forgetting your point 3rd here is what I can tell you:

• Tape won't resist time under industrial environment. You need to keep them in a dry zone with a constant regular temperature (it does hates humidity and high temperature variation).
• Ignoring point 2: DVD is still a good way to keep your 10 year. You just need to buy DVD with a high quality. Be warned: lifetime warranty is considered to be 5 years. So be sure that your DVD is 10 years warranty and burned with a low speed (the higher speed the more you put errors witch, in time, will turn into definitive errors due to the time decay of the DVD).
• Last but not least: you buy a very specific technology (like Iomega Zip at that time) that is native with Linux. you buy various readers/burners and use only one at a time. Linux compatibility will ensure you 10+ years of support of your drive (not the case under Windows). If your device comes down then you replace it with a new one that you buy and if you can't find it you use the one that you kept.

You must consider to make your backup plan over a 5 years cycle and store your backup media in a stabilized normal environment.

5 years is the longest secured timespan of a device. Over those 5 years you automatically take the risk to loose your backup because you have no more warranty of your device.

That means that, for whatever technology you use: you must redo/convert your backup media every 5 years as your platform changes.

There is also another consideration to take that is almost more important than your storage: Where is the possible target of your restore plan? In a 10 years lifespan many of those devices are dead or evolved making your backup useless or at least make your restore plan a nightmare. That is why 5 years cycles are better because you can make live your data with the infrastructure evolution.

Answer 2

If you are looking at a single media which you can use for 10-20 years as a backup or storage device, then it will be difficult. All of the current backup solutions require access to a computer and have a shelf life. And a computer generally has a max shelf life of 7-10 years. After 7-10 years getting a new computer which can consume the same media is dicey to say the least.

The best solution is as follows

1) As of today, i.e. 8-Oct-2015, Keep 3 external, non-Flash non-SSD, drives to backup your data. The quantity 3 has been chosen for having redundancy and if one HDD fails then you have the ability to still access your backup.

2) After 3-4 years or when you buy a new computer in the future, look at the most economically backup at that moment of time and move your data to the new backup. This may also entail modifying the file format from one to another. If when you buy a new computer the most economical backup is still a USB HDD then by all means stick to it. But repeat this every 3-7 years when you buy a new computer.

Please note that it is assumed that

• the file format that you are using to backup your data will still be around

• you will have applications and a matching OS which can run those applications in the future which can consume those file formats.

If you are comfortable with cloud storage then one can use Google Drive and/or Amazon AWS services too. That will also allow you to have data storage if not for 10-20 years then for some years in the future. However if your backup size runs into multiple hundreds of GBs then please factor in the cost of bandwidth and the time taken to upload and download the backup files.

What you are looking for, i.e. 10-20 years of backup, is generally required by libraries or Universities or Government departments. Since these are corporate entities or organizational entities they have agreements in place with various companies to provide them this service. So for example IBM or some other company will have a contract which says, that IBM will backup say 100 GB of data every month for say 7-10 years with certain cost escalation. These companies then maintain the hardware and software so that the data can be accessed. If you are part of a corporate entity or an organizational entity then one can approach these companies. However if one is an individual or a simple retail customer then it is not possible to do so.