Sometimes, despite your best efforts, data loss can happen in your company. Whether the data loss is caused by physical damage to the storage devices, viruses, or the actions of a disgruntled employee matters very little in the steps needed to restore your data. Data loss can affect your business in a variety of ways depending on what kinds of data your business stores. A loss of customer contact information may make it nearly impossible to continue to do business while a loss of private medical information could mean a lawsuit, a hefty fine, and a public relations nightmare.
The first step in data recovery is to ensure that data you need to keep is secure. By maintaining off site backups as well as duplicating data within the company you can take quite a bit of the sting out of a data loss incident. In fact, depending on what kind of data loss has occurred a backup may be the only method available for restoring data.
The process of restoring data depends quite a bit on how the data was lost. The most common ways data is lost include viruses, physical destruction or failure of the hard disks, and employee malfeasance. By looking into each of these causes in detail and assessing the responses to that data loss, it should become more clear how data recovery works as a process.
If data is lost due to a virus you have the unenviable situation of not knowing if your backups are infected as well. Some viruses are designed so that there is a delay between the initial infection and the destruction of your data, for the sole purpose of hoping the virus is backed up with the data before it is noticed. Because of this if your data is lost due to a virus infection, you will want to restore it first to a test system that is not connected to your company intranet or to the internet. If connected to the intranet there is a good possibility that the virus will spread and re-infect your other computers, and if connected to the internet the virus may be stealing data and sending it to the virus creator. By restoring the data to a standalone machine you can determine if it is infected and remove the virus before restoring to your live systems.
Physical destruction of the hard disk comes in two broad categories, actual physical destruction of the device, and failure of the device electronics or hardware. Most data is stored on a hard disk, which contains a multitude of ceramic platters coated with a microscopically thin layer of magnetically sensitive material. Floating above these platters are a series of read and write heads which can either magnetize or demagnetize the sections of the platter, and this is how data is written and read from the disk. The platters themselves are fairly delicate and can be destroyed by dropping, and if the read/write heads are to impact the disk it can cause grooves and furrows in the platter that will cause it to fail to read.
There are specialized companies out there that can generally read data from a damaged hard drive, but those services are extremely expensive and should be reserved for situations where all other data recovery options have been exhausted.
Finally, there is data destruction due to an unhappy employee. It is unfortunate but an employee who gets wind of an incoming termination will occasionally decide that they wish to harm the company before they lose access to the data. One of the best ways to prevent this is to make a termination decision after hours, and as soon as the decision has been reached deactivate the employee's access to all information technology resources within the company. By also deactivating their badge, assuming your company uses badges to open doors, you can have security catch them right at the door the next morning and hold them while you come down to deliver the news. By doing this you can ensure that a former employee has no unsupervised time in which to destroy company property or data.
If an employee manages to destroy company data though, chances are he will simply delete large swaths of whatever data he can get into as quickly as possible, which means he's not going to do a particularly thorough job of it. When data is erased from a hard drive the operating system simply marks the sections of the hard drive that formerly contained the data as empty and writes over them the next time they are needed. The data is not actually deleted and can easily be recovered by a multitude of tools designed for this exact purpose.
To sum it all up, by ensuring that your company maintains good backups and a solid termination policy, you can ensure that your data continues to be there when you need it.