Monday, January 19, 2009

Backing up backups

Be it a corporate or an individual, backups are essential -- though not many individuals realize until the disaster strikes. This post is only about individuals.

Are you an individual who regularly backs up your stuff and feel good about it? huh hold on. Maybe not, you might be missing to do something.

While the number of people even thinking about backing up their stuff is minimal, you don't have to ask about number of people who would want to backup their backups. But in my opinion that's very essential based on the backup medium that you have chosen to backup.

There are three things one has to worry about:
  1. The lifetime of the data in the media
  2. The lifetime of the media's technology
  3. Disaster recovery
In my opinion, the most common means of backing up is on CDs (and recently DVDs). But how long does the data stays on the medium? The answer depends on a variety of factors including the quality of the DVD, quality of the dvd-writer, storage environment (humidity, temperature etc.,). While there are PIE/PIF tests to measure the quality of the medium, it is still not very easy to manipulate and ensure the life-time of the data on a CD/DVD to an acceptable degree of accuracy. The lifetime can even be as low as few months to as good as 15+ years. On an average the data on a DVD is claimed to live for about 10 years (a side note: there seems to be some manufacturers to seem to be selling high quality DVDs which would last for 100 years -- possibly true on the quality of the medium). So on an average, what you had backed up 5 years ago is only going to live for another 5 years -- scary? but that's the fact.

This is when backing up the backups seems essential. For peace of mind, you might probably want to backup the backups every few years and shred the old copies -- this to me is the easier and safer approach, but expensive (btw, data is priceless). On the other hand, you can choose a media that has a longer lifetime. Well, I personally don't trust the magnetic hard disks for long-term backups. They have new factors coming in as issues like shock, magnetic exposure etc., (maybe solid state disks can be a future option). So another possible option is to choose an online backup mechanism, where you push your problem to someone else (for maintaining the data) and pay a premium. Yes, the factors of reliability and privacy comes in here. Privacy can be handled by key based cryptography but reliability is still a concern here -- what it the company goes bankrupt? -- nothing new as of today. I've no specific recommendation, neither do I know of enough options.

The second issue being the lifetime of the media's technology. I would not be happy to have backed up my data for the last 15 years but only to know that I can't read the data because it was all in floppy disks! Floppies are almost extinct now and it is many years since I used a floppy. This is mainly due to data explosion wherein 1.44 MB of data is almost negligible these days. It was fortunate that it turned out to be a smooth move from CD to DVD's as the technology is similar and the DVD drives were able to read CDs -- this isn't necessarily true as the technology evolves further. I know so many people who still have their marriage videos in VHS cassettes -- you should remember that this was a conscious decision they took to save those moments for the future. Today, either the cassette would have gone bad due to fungal growth or they would not find a VHS player to enjoy the show. They didn't intend to lose it, but they didn't know. Solid state disks are becoming popular and are seeming to be the best bet for portable use and being read/write'able. The point is not about what would be the next generation storage medium but about the fact that whatever it is, there is no guarantee for it to be backward compatible.

The last thing is the 'disaster recovery' -- what if there is a physical damage to the medium due to natural calamity, fire, theft etc., This is one of the difficult problems to solve for an individual. The only solution is to keep a copy but that risks privacy. Maybe an online backup coupled with a personal media backup might help...

So please be aware of the problems upfront; finally the data is yours and the decision is yours.


  1. all these days we run over so much personal data, sometimes we don't even find time or memory (that such a data exists) to look back at them :-)

  2. True. Even I've lost tonnes of data. You would know the amount of 3D animations work I had done in college (and all those movie collections that we share in hostel?) -- I've lost them all :(. one should realize the need for backup, then it becomes a habit.

    Like how they say 'the best way to remember your wife's birthday is to forget it once', I would say 'the best way to remember to backup is to lose it once' :)