Hard Drive Erasers vs Degaussers
Both hard drive erasers and degaussers will render data stored on a hard drive inaccessible, but they use different technologies to do it, and with one crucial difference. If you use a HD eraser, you can reuse and redeploy the drive. If you erase a hard drive with a degausser, you won’t be able to reuse the drive.
So, what next? How do you decide if you need a hard drive eraser or HDD degausser?
The Pros and Cons of Erasing vs. Degaussing
The biggest advantage in using an HDD eraser over a degausser is that with a software overwrite program the hardware remains unaffected and so the hard drive can be reformatted and immediately redeployed. Overwrite hard drive erasers have another advantage over degaussers in that certain degaussers have a slot or drawer in which the hard drive must fit. If the HDD’s physical dimensions exceed the maximum dimensions for the unit, then the drive cannot be degaussed in that degausser. In addition, HD erasers can usually erase multiple drives in one operation (as many as 20 or more per pass), whereas most degaussers only accept one drive at a time.
Degaussers have an advantage over erasers in that the drive does not need to be working in order to be erased. Because the HD eraser actually interfaces with the drive, hard drives must be functioning in order to be erased by an erasing unit. In addition, overwriting programs skip over any bad blocks on the drive. In addition, certain models of degaussers would be able to process larger volumes of hard drives, which would be especially convenient in a large data center that is decommissioning hard drives at the end of their lifecycle.
The Benefits of Degaussers
As a general rule, if you wish to eliminate all information from your computer hard drive and then dispose of it, the best method is using a degausser of proper strength.
An alternating current (AC) bulk degausser will completely erase data and all other signals recorded onto your hard drive and other magnetic media. Degaussing is a process where magnetic media is exposed to a powerful, alternating magnetic field of sufficient intensity to completely saturate the media. Degaussing removes all previously written data, leaving the media in a magnetically blank state.
Any magnetic media that contains pre-recorded servo tracks, or tracks that instruct a device in how to interface and thus read the media, will be rendered useless after degaussing, because a device (such as a computer or tape drive) won’t be able to access it. Examples of this would be computer hard disk drives and certain types of computer tape such as LTO, Magstar 3590, and StorageTek 9840 and 9940. Hard drives do not need to be working in order to be erased by a degausser.
The Benefits of Hard Drive Erasers
However, if you need to erase and then reuse your hard drive, a software overwrite erasing program is the only solution. A hard drive eraser will permit you to completely erase the data from the media and still reuse it, thus potentially saving your company thousands of dollars.
With hard drive overwrite software, the eraser simply writes over every working data location on the disk one time, so sector and servo information remains on the disk. However, your HDD must be in proper working order for a software overwrite to be able to work – the software will skip over any bad blocks on the drive. The Department of Defense has rigorous requirements for security erasure, and under this specification the disk is overwritten eight times so no electronic pulse of any kind remains on the disk. This procedure has DoD and NSA approval.
