Hard drive data recovery - The big picture

Introduction

Hard drive data recovery remains at the core of our business, with the prevalence of these spinning disk devices now greater than ever. Over 35 years on from their introduction into the commercial market, hard drives have become an invisible yet integral part of so many aspects of our lives.

The chances are that whenever you are on your mobile phone checking Instagram or Facebook, watching streaming video on your TV, doing an online shop on your tablet or interacting with computers at work, the information that you are consuming is ultimately stored on a hard drive somewhere in the world. Whether it is a device in your home or a hard drive in a rack in a data centre, we rely on and take this technology for granted.

Our multimedia fascination means we generate and consume vast amounts of digital content in the form of photos, videos, music and documents around the clock. This data has to be stored and accessed as quickly and efficiently as possible and modern hard drive technology is still the most cost effective way to achieve this.

Hard drive usage

As a Data Recovery service provider we see hard drives from all types of devices. With a low cost and high capacity they are the best option for data storage in most scenarios, except perhaps in smaller tech devices such as Mobile Phones, Tablets and Digital Cameras, where size and power consumption limits their use.

Hard drives are perfect for desktop PCs, Laptops, Servers and NAS boxes that are often in constant use and require large amounts of storage space for programs and data.

External USB drives are popular as back up devices or for portable storage purposes, unfortunately these devices are easily dropped or knocked so are a regular in our labs. 4TB USB pocket drives and 10TB desktop external drives are now common, providing huge data storage potential to the home user market.

Hard drives (HDD) vs Solid State drives (SSD)

The alternative to hard disk drives are chip based Solid state drives. These are smaller, faster and contain no moving parts, which makes them ideal for portable or smaller devices. Unfortunately SSDs are still expensive in comparison and are susceptible to power fluctuations. From a data recovery perspective it is usually harder to extract the information, but recovery techniques for these are improving all the time.

A comparison of the three main storage options

	Pros	Cons	Summary
HDD	Large capacities Relatively cheap Greater tolerance to power fluctuation Easier to extract the data if they do go wrong	Mechanical moving parts are susceptible to damage from knocks or being dropped They are bigger and heavier than SSDs	If your device is sitting on a desk and doesn’t move go for an HDD, the greater capacity really is the huge selling point. It’s better to have multiple HDD’s inside of a device rather than external cases as this offers greater protection.
SSD	Very fast Small No mechanical moving parts Can be moved around without fear of damage	Still expensive Susceptible to power fluctuations If they fail it is usually more difficult to extract the data than a HDD Lots of fakes being sold online	If your device is moving around a lot (commuting or out in the field) then go for a good quality SSD every time. If you can always use a surge protector on the device the SDD is in or plugged into.
Cloud	Someone else is looking after your data Accessible anywhere in the world as long as you have an internet connection Easy to use No physical drive to worry about Small amounts of data are usually free or very cheap	Someone else is looking after your data Moving large amounts of data can be slow and get expensive	You should have a cloud account but look very carefully at what you actually get and make sure it has been set up correctly. Internet speeds are a limiting factor so a combination of physical drives and cloud is the best way to go. Nothing is fail safe, we have done too many recoveries for data centres to trust cloud on its own.

The evolution of Hard drive data recovery

Hard drive technology has come a long way since its’ inception, whilst the fundamental components have remained the same, the technology has improved to allow faster read/write speeds and higher capacities.

As with any other mechanical device, hard drives have a limited life span and are susceptible to damage or failure resulting in data loss, so this is where data recovery specialists come in.

Professional Data Recovery software, tools and techniques have all advanced in line with changes in technology and the industry continues to innovate and invest resources into R&D. Add to this the wealth of knowledge and experience that has accrued over the years there is a high chance of getting your lost data back.

Types of data recovery

Generally speaking data recovery techniques are categorised as logical or physical. Logical recoveries are often straight forward and can be achieved using advanced data recovery software. This still requires technical knowledge of hard drive technology to understand the type of data loss and ensure all files are recovered safely.

Physical recoveries are often separated into those that require engineering work and those that require spare parts or components. It’s common to use multiple techniques through the recovery process, especially when drives have more than one fault.

Modern Data Recovery

New benefits bring new challenges

Improvements in the technology have benefited consumers, but made some aspects of the hard drive recovery process more challenging. Although the speed of the hard drives has increased, so has the capacity, meaning the potential for a huge amount of data on a drive. Copying lots of small of files takes longer than copying fewer large files, in our experience it is the quantity of files rather than the file size that we have seen increase.

This can have implications on the time it takes to get a customers’ data back, it can also effect the overall success of a recovery. If a hard drive is in a particularly bad state there may be a limited time window to recover the data before the drive inevitably fails. This means we have to be vigilant in assessing the condition of the drive and its’ potential for failure and take an approach that gives us the best chance of recovery. It’s important in these cases that we target the customer’s most important data as a priority. These recoveries need constant observation and on many occasions an engineer’s intervention during the recovery process.

Mechanical repair and component replacement

Mechanical repairs on hard drives are not as straight forward as they use to be, this is where the combination of technical knowledge, engineering skills and R&D comes into play.

It is still possible to replace a hard drive head assembly with components from a similar drive. In more recent years the head assemblies are more uniquely tied the specific model during the manufacturing process. This means that a donor component must match various factors depending on the make and manufacturer of the drive.

Replacing a spindle motor or transplanting the disk platters to a new hard drive assembly are pretty much things of the past. Many aspects of the mechanics are calibrated to precise tolerances during the production process and this would be more difficult to achieve outside of that environment. While not totally impossible, this type of work is out of the scope of most commercial data recovery companies.

Software fixes

Hard drives maintain a service area (SA) on the disk, which is a storage area not usually accessible to the end user. This area contains the various modules of data and code (including the firmware) that are needed to operate the drive. This area can become corrupted making the drive unstable or the data inaccessible.

Modern data recovery tools allow access to this area to fix damaged software, upgrade firmware or even bypass it entirely. Vendors do not really want people to have access to the service area, so these tools are constantly being improved and updated by ongoing R&D within the industry to provide support for the latest devices.

External hard drive data recovery

USB External hard drives are very susceptible to physical damage and can present unique challenges of their own. In many cases the drive can be removed from the external caddy and recovered in the same way as other hard drives, however it is now more common now for USB drives to include additional technology.

Some USB hard drives have technology known as SED (Self Encrypting Drive) which includes more advanced hardware encryption, this can create a bigger challenge to recover the data.

Quite often the USB controller gets damaged which adds another layer of complexity and is compounded to any other underlying physical or logical issue.

It is also incredibly common for damage to occur to the USB connector, due to the compact form factor and their portability.

SMR Technology

Advances over the last 10 years have seen the introduction of SMR (Shingled Magnetic Recording) technology on the disk platter surface. By overlapping the data tracks it allows for much higher density of data storage on each disk. Due to the nature of this technology data is constantly being moved around to maximise the storage efficiency. While the technology has greatly increased hard drive capacities it has also increased the potential from problems and complexities within the recovery process.

Causes and types of faults

The faults we encounter have not changed much over the years, the challenges we face are often to do with advances in technology of the existing components. Manufactures strive to produce faster and higher capacity devices which push every aspect of the technology involved.

There are some common faults which are relative to the device that the hard drive comes from, but to be safe it’s best never to make assumptions on the nature of the fault and do a thorough evaluation before starting the recovery process.

Some of the more common faults are:

Drive is making a Clicking noise
Drive is making a Beeping noise
Stiction
Spindle motor ceasing
Bad sectors
Physically Damaged PCB
PCB corrosion down to heat/environment, smoke dust
Firmware corruption
Device not recognised
Deleted files
Water/liquid damage
No power to the device
Corrupted files
Virus or Malware
Head failure

Drive error vs user error vs Machine error

Data loss is not always down to the hard drive or containing device, user error is just as common. This is mainly down to accidentally (and sometimes deliberately) deleted files or where a drive has been formatted by mistake. Accidents where devices are dropped, liquid is split on them or they are mishandled are also very common.

Facing the future

Hard drives are such a large and integral part of legacy and developing IT infrastructure that their dominance in the market place is likely for the foreseeable future. As drive technology continues to improve to provide better performance and higher capacities, it remains the most cost effective way to store large volumes of data.

Data recovery service providers continue to innovate and invest time and resources into R&D to provide the best chance of recovery in the event of data loss. Even with the emergence of cloud storage and other cost effective backup solutions, there is still huge demand for data recovery services. With more hard drives being used and more data being stored this is set to continue.