Backup & Recovery

So Employee "A" is sitting there playing with astoundingly powerful magnet right next to their computer with a pile of hard drives in it all whirring away. Not far away, a nice 19 inch monitor sits patiently waiting to be permanently wrecked if the shadow mask gets magnetised. Of all the things that people know you're not meant to ever do, our employee is probably doing it right now.

But in theory you can wave a hand-crushing neodymium-iron grungy magnet quite close to computing devices in perfect safety nowadays, surely? After all, magnetic field strength falls off roughly with the cube of the distance. That's a horrible approximation, of course, but quite a useful one. It does mean that fairly small magnets cause no ill affects to computers and anything the size of a marble is OK if it doesn’t get any closer than 30 odd centimetres away. But, even though your hard drive is protected from these sorts of effects, it does mean that the magnet the size of an iPod needs to be roughly a metre from your PC or your monitor and laptop will be permanently soup.

This also explains why the magnets in your laptop bag (the size of a very small, small thing) don’t toast your laptop every night. So, magnetic fields and magnetic storage media do mix, sort of, just as long as the magnetic field isn't really amazingly strong. So is it a fallacy that magnets stew hard drives? Sort of, yes and no, magnets do cause damage to monitors and hard drives, however, they don’t "zap" the data as such.

Hard drives and floppy disks store data with tiny magnetic spots on the media. When the read-head passes over these "spots" it reads the space as either "1" or "0". By placing a magnet next to the client media (not DVDs because they’re optical), the "spots" will be altered, either by turning them all to "1" or all to "0" (depending on the polarity of the magnet), wherever the magnetic field reaches. But the field has to be pretty strong, because it has to exceed the coercivity (or the intensity of the magnetic field needed to reduce the magnetization of a ferromagnetic material to zero after it has reached saturation.) of the magnetic coating on the storage device.

Hard drive platters have a pretty high coercivity, which means a magnetic field of the same strength is needed to demagnetise them. Usually, most magnets won't endanger hard drive data even if the drive's right next to it, unless, that is, you put it down on top of the drive itself, which is, unfortunately what our employee did.

So, yes, magnets do damage your data stored on computer devices. But it’s pretty difficult to explain to your average Outlook user why it does. In order to avoid confusion in the minds of the proletariat I would fabricate a more easily explained conventional wisdom, along the lines of: "Don't put a magnet near your computer, or, roughly speaking, your brain will decompose suddenly and you’ll see blue."

Most of the time we’re OK though – notwithstanding leaving extremely strong magnets on our computers - I have heard say, however, that you should buy yourself an anti-static wrist strap and earth yourself to the national grid while you work on your computer, or touch the chassis metalwork periodically while you work, to prevent your PC turning into toast.

Apparently, it's possible to destroy hardware with static discharges smaller than a couple of hundred volts. You won't even feel that, and you can build up that much of a charge on any fairly dry day, while sitting in a perfectly ordinary chair. But telling people that just breathing makes them into chip-killers is completely alarmist. Modern computers are riddled with highly static sensitive complementary metal oxide semiconductor chips. But, evidently, lots of people not only use PCs daily but assemble and upgrade computers without taking any particular precautions, and the PCs proceed to work - weird.

But there are things that will toast your PCs which then develop horrible stomach-turning instability issues. Spikes damage sensitive electronic equipment and can alter and damage data. They can "take out" an IT system through damaging internal circuitry, occasionally damaging equipment beyond repair. However, most often they cause hardware to behave erratically, resulting in disk write errors and lost data.

Although the computer age races forward with desktops and laptops having foreshortened shelf lives as newer and bigger and faster technologies take over, we take power supply for granted, electrical power is a constant in our world, or is it?

The first working prototype engine built by Rudolf Diesel in 1892 bears little resemblance to the diesel engine cars of today, but fundamentally, the production of electrical current has not changed since Edison Electric Light Company was formed in October 1878, which delivered, amongst a plethora of other significant inventions of the era, the first electrical power distribution system. Surges, spikes, blackouts (or power outages) and brownouts are not uncommon and we have already seen major power outages in the US and Europe in the last few years. It is fairly safe to say that every organisation will experience some sort of power fluctuation that could potentially threaten their business. In fact, power fluctuations can disrupt, if not halt, an organisation in its working tracks.

We tend to associate disasters with natural disasters, earthquakes, hurricanes, floods and man-made disasters, wars and terrorism. However, around 38% of all disasters are caused by power problems. Unlike other disasters both power fluctuation or outage and human error can easily be managed. Failure to plan for power protection will leave your business vulnerable, customers dissatisfied, with staff unable to work until the systems reboot and the lights go back on.

Businesses affected the most by potential power outage are health, financial and e-commerce sectors, and in some cases these situations are life and death. So not only do you have to ensure you have a robust data protection plan in place but determine a power protection plan that is best suited to your business.

Power fluctuations of various types attack computers every month. Studies have found that corporations lose millions each year due to power problems. Businesses in areas with frequent thunderstorms are at a high risk, as well as those in heavily built up areas with either high domestic utility or business demand. Even simple things like linking via modems or being too close to business equipment such as copiers, printers, or lifts can affect power. Basically, all businesses that rely on electronic equipment are at risk from power failure or fluctuations, in fact, your equipment is in danger of being damaged every time you turn it on.

There are 5 main dangers:

  • Spikes are sudden burst of excessive electric current and usually occur during electrical storms. Spikes cannot only damage sensitive electronic equipment but can alter and damage data. They can "take out" an IT system through damaging internal circuitry, occasionally damaging equipment beyond repair. However, most often they cause hardware to behave erratically, resulting in disk write errors and lost data.
  • Surges are less intense increases in voltage, but last longer than spikes and are more common. They can be caused by heavy electrical equipment being turned off, such as air conditioning units. They are relatively regular occurrences often resulting in hardware disturbances
  • Brownouts are temporary drops in voltage below standard levels that can cause computers to shut down. Brownouts can be caused by; electrical shorts, the overloading of the local power lines when a large electrical device is turned on – like air conditioning units. Brownouts are the most common power problem. They can cause extreme damage, such as loss of unsaved, vital data in RAM, loss of data being written to disk, and erosion of a system's hardware components.
  • Blackouts are a total loss of power for extended periods of time. Caused by bad weather, network power failures, short circuits and network disasters. Blackouts cause the loss of unsaved data; total system outages; the erosion of hardware components; and the possible failure of the file allocation tables on the hard drive, making it impossible to locate any data on the hard drive.
  • And then there is also noisy power. Noisy power is the result of electromagnetic energy caused by other electronic equipment located nearby. Noisy power can alter the quality of power, which wears computer chips and can result in disk write errors.

Deciding on which power and data protection strategies you use will depend on your business. Sole traders, working from home should at least invest in some basic backup software and probably a surge suppressor that fits between the PC and the power outlet. Surge suppressors are the cheapest form of protection and suppress incoming spikes and surges before they reach your equipment. They prevent spikes and surges from harming hardware components; however, they do not stop the loss or corruption of data. A more robust solution is a Voltage Regulator or Critical Conditioner. These are designed for single computers or small servers. They eliminate spikes, surges, brownouts, and noise from incoming electricity to deliver clean, regulated power to your system; Critical Conditioners actively regulate voltage that's too high or too low.

Larger companies need to assess applications, equipment, goals, and time. The same decisions made about data protection should be reflected in how much outage you can afford. How crucial it is for your organisation to stay online? What applications and equipment need to be protected? If power outages can potentially disrupt data communications, erode your hardware, and potentially culminate in a hardware failure the need for specialist consulting to assess business risk for business continuity for both power and data recovery is essential.

No one can presume that they are not exposed just because they’ve never had a power problem before. If an organisation is thinking about re-vamping their data centre, putting together a data protection plan, then power protection needs to be a part of that plan. With the predominance of "Green" computing issues beating at the CIO’s door, it is imperative, even from a cost point of view for IT to re-think how we use every watt of power in the data centre.

If you’re fortunate enough to be running a Symantec backup product even if you do set fire to your PC in the most bizarre way possible you’re safe in the knowledge that you can recover from the hell that is loosing our PC. Had our employee backed up their laptop and their work? Well, actually, they couldn’t remember. Thank goodness for policy based management!

Administrators can simply force us all to do what we should be doing anyway, so the last image backup from our infamous employee’s laptop was the morning of their unfortunate game of death with the magnet, and according to the Backup Exec System Recovery Desktop Edition agent the last backup was completed successfully, so they didn’t very lose much after all.