Data recovery FAQs: what is a head crash?

The head crash is, amongst those operating within Information Communication Technology at least, truly infamous. It’s one of the most common causes of hard drive failure and data loss. As a result, it’s both despised and feared by IT professionals and expert data recovery technicians in equal measure.]

But just what exactly is a head crash? Well, before we explain, we’ll need to provide a bit more information about how hard drives work.

How hard drives work

Hard drives store data by using components called read/write heads to record data onto a separate part of the drive known as ‘platters. The heads write either a one or zero onto microscopic sectors of these platters by magnetizing or demagnetizing them. The sectors that contain the data that comprise a file are then recorded by the drive and, when the file is opened, the read/write head reads what is stored in these sectors and the file is opened.

So, the key takeaways here are that all data is stored in a hard drive’s platters and that this data is both written to and retrieved from these platters via the drive’s read/write head.

So, what is a head crash exactly?

You’ve probably already realised that a head crash will involve both a drive’s read/write head (the clue’s in the name) and its platters, but it’s how these two elements interact with one another when a head crash occurs that make it such a potentially catastrophic occurrence.

A head crash occurs when a hard drive’s read/write head comes into contact with its platters. Usually, these are held just a few millimetres above these discs but, whether due to a mechanical failure or damage to internal components, they can come into contact with the platters – and data loss is an almost inevitable result.

Platters are coated in a thin film of a material that can be magnetized or de-magnetized and it is within this coating that data is stored. When a drive’s head touches the platter, it strips this coating away – taking the data that was stored there with it. This is often made worse by the fact that users – unaware of the possible reason why their drive is failing to boot up – continuously try and try to access their files after a head crash has taken place, with the head stripping away more and more of this coating in the process.

Identify a head crash and minimise the damage

If your hard drive is making a grinding sound or spinning frequently without actually booting up, it’s possible it’s suffered from a head crash. Power it down immediately to prevent extensive data loss and book a free data recovery diagnostic with us ASAP!