Steve Lane, PC PAL franchisee for Leicester South and Market Harborough writes:
A few weeks ago a customer asked me how a hard drive might become corrupted. I answered that it could be a number of things from power spikes to cosmic rays. He retorted some comment about cosmic rays and I think he thought I was pulling his leg a little. But the truth is that cosmic rays are energy particles originating from outer space that can have an effect on electronics. Our sun emits low energy cosmic rays which increase in intensity during solar flares.
The effect on computer electronics can be quite considerable. The computer works by using states to indicate if a bit is storing a one or a zero. You can think of it like a light switch. When the light is on the state is said to be representing one. When it is off it is said to be representing a zero. By using a series of ones and zeros we can represent something like this document I am typing. The letter “A” for example is represented by the binary number “01000001”. Cosmic rays although low energy have the ability to flip the switch. So it could transform a letter such as changing the word “tender” to “sender”.
In October 2008 cosmic rays may have been responsible for causing a Quantas aircraft to nosedive twice leaving eleven passengers injured. The wrong data was sent to the main computer from the “data inertial reference unit”.The consequences of the wrong data being sent could have been much more serious. Computers these days are ubiquitous such as controlling engines in our cars, controlling the flow of electricity, air traffic control or equipment in operating theatres. Computer information is relied on to make life or death decisions. So flipping the switch and changing the data in a safety critical system may cause a catastrophe. Fortunately, most of these systems do have a way of checking and recovering from spurious data. However most home computers do not use these error checking routines, so cosmic rays are a fact of our computing life.
In the home or small business computer there is not much we can do to stop the cosmic rays. We can however be prepared for data corruption or loss by implementing a best practice backup and recovery strategy.
Here are 5 best practices that I recommend: -
- Decide what you need to backup and how often. A question you could ask yourself is “What data could I not do without for a day/week/month or if I could not ever get it back?”The answers to these questions can determine how often you backup.
- Backup to a local source such as an external hard disk, USB key or to a rewritable DVD
- Use an online backup service that automatically backs your data up so that you have an offsite copy of your data – we can advise you on a suitable service for your home PC or your small business
- From time to time, test if you can restore. Make sure you the files that you think are safe are really safe.
- If you are a small business, start to think about disaster recovery and business continuity planning. What would you do if you suffered major data
In my next blog entry I will be looking at the whole subject of disaster recovery and the common steps that any business can take to ensure that after disaster strikes business can continue.'
Steve Lane (PC PAL, Leicester South & Market Harborough)
