Time is taking a Byte out of your backups

Date:23 January 2015 Author: William Horne Tags:, , , , , , ,

So you’ve headed the warnings of the experts and you’ve been fastidiously backing up your precious data on which so much of our lives now depend, but we’re afraid you’re not out of the woods yet.

Digital information, or data, is not friends with the laws of thermodynamics. Although your accounts, wedding photos and that novel you’ve been working on for several years now, is safe from theft and freak floods on your new backup external hard drive, there’s no escaping the slow decay of digital information in the physical world it is kept in.

Depending on the medium of storage you are employing to store your data for the long term, there are varying degrees of decay associated with each storage device.

The reason this doesn’t sound as gloomy as it should is probably because the digital era is still very much in its infancy and, simply put, we’ve essentially packed up and moved to a new country, but we just haven’t been living there long enough to know what winter is going to do to our new homes.

The move to digital has seen us moving every facet of our lives to electronic storage. But we’re still in a frame of mind where we think that as long as you keep the device securely stored in a locked cupboard, like the filing cabinets and photo albums of old, it will last as long as it needs to – say a few decades, at least.

But digital storage works differently to that.



Flash Memory

The flash memory your camera, smartphone, tablet and, increasingly, laptops work on is not designed to be a long-term storage solution. In fact, you can expect little more than a 3-5 year average depending on the amount of decay you induce by copying and deleting information over and over. But keeping the device in more than 25 degrees Celsius is a sure-fire way to lose data within less than three years according to the JEDEC JESD218A endurance specifications for flash memory.

Hard Drives (HDD)

When it comes to your hard drives, the outlook isn’t much better. In active use, the constant physical writing and rewriting of data degrades the ability of the drive to be able to retain information. But even when turned off, the magnetic disc is susceptible to thermal erasure, whereby the kinetic energy of the atmosphere around the disc causes it to lose data. Combining these considerations with the fact that HDD’s have numerous moving parts that can fail and cause damage, the average lifespan in an active archival function is about 5 years.

CD’s and DVD’s

Blank discs have a lifespan of about a decade, while written discs average around 5 years. Under ideal storage conditions and minimal use this can reach between 10 and 15, and in exceptional cases, 20, but this does not account for the fact that reading discs causes damage to the highly sensitive optical storage medium. Essentially, your holiday photos and that copy of Saving Private Ryan won’t be around for all the time you’ll have available during retirement, like you thought.

Magnetic Tape

Turns out, this probably has the best practical long term storage capacity available, if stored correctly. Archives the world over are initiating moves back to magnetic tape (yes, exactly like the ones in your old cassettes), because they have storage longevity measured in decades; cost little to nothing; and have large capacities for their size.

For the average consumer, magnetic tape is probably not the solution. And this article is more to prepare you and inform you than it is to provide clear cut solutions. But this is the nature of data, and below you’ll see a video of how copying and pasting data also decays the information. Here it is in the form of a few thousand uploads and downloads of the same video to YouTube over time…

Maybe magnetic tape isn’t such a bad idea, after all.

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