Edition 52
Some Spin About Choosing Your Storage Media
by Lee Sensenbrenner, Director of Product Marketing, Gillware Data Recovery

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In the event that a data backup didn’t work or never existed and it’s necessary to recover data from failed hardware, the task varies considerably based on the wide range of storage technology available today. One of the most obvious divides that’s emerged – particularly among laptops or anything mobile – is solid-state storage versus traditional hard drives. This article is a brief primer on how data recovery differs between solid-state storage and traditional spinning hard drives – something that often is not a consideration when choosing hardware.

Hard drives have existed for more than half a century and still seem to be the future for many desktops, servers and enterprise applications. Hard drive manufacturers also have not conceded the laptop market, and are producing slimmer drives to compete with SSDs. But most laptops, tablets and mobile devices on the market come with solid-state storage or offer it as an option.

Data recovery labs have decades of experience repairing hard drives inside clean rooms, imaging them, and solving logical puzzles to retrieve the data. In the hands of a competent data recovery lab, the primary barrier to whether data can be recovered from a hard drive is whether it, and its essential logical structure, still exists on whole platters. In other words, if the bits that comprise the important files haven’t been physically scratched off by something dragging on the spinning platters, it hasn’t been overwritten by other data or demagnetized, and the platters haven’t shattered, there’s reason to expect a good lab will be able to get it back. There is quite a range of complicating factors here – drives can be exceedingly rare and difficult to find parts for, various levels of encryption can stymie efforts, and logical structures of some file systems can pose some serious challenges. But on the whole, the approach to recovering data from a hard drive is familiar to qualified data recovery labs.

In contrast, some forms of failures among solid-state drive require cooperation with the drive’s manufacturer to allow cost-effective data recovery.

Gillware Data Recovery looked at how solid-state recovery differed from hard drive recovery in white paper published in 2009, when the incidence of solid-state drives showing up for data recovery was newer. Since then, Gillware, as well as other top labs, have worked with the manufacturers of solid-state storage to help make recovery more reliable and cost effective.

People are generally familiar with how spinning media keeps its data. Even if the actual technology is different, the concept, thanks to the record player, is easily visualized. A hard drive has discs with magnetized surfaces. The 1s and 0s lie in concentric tracks, which pass under moveable read/write heads. If the read/write heads stop working, or the motor that spins the discs burns out, the data still exists as magnetized patches on the discs. Once the mechanics are restored, the data can again be read.

Solid-state data storage is physically different; there are no moving parts. But before looking at how solid-state data storage works, it’s important to look at another reason data has to be recovered, and that’s a failure of the logical structure that makes it readable.

Logical failures can happen in hard drives or solid-state drives. The data on any drive has to be thoroughly organized for a computer to access it reliably. There are many different file systems that accomplish this, and for Windows operating systems, popular ones are NTFS and FAT32.

For an NTFS example, let’s say a drive’s organizational structure starts at Sector 0 with a partition table, which is part of a Master Boot Record. The partition table shows the basic divisions within the hard drive. At the beginning of the partition is a boot sector. The boot sector gives the location of the master file table, the root directory and the bitmap in relation to the boundaries of the partition. The master file table is constantly changing with the data held on the partition. It is a record of all the file names and where they live. The bitmap tells your hard drive where data has been written. When some of this metadata is lost, information may become inaccessible because the hard drive loses the framework it relies on to find its way. Missing boot sectors, partition tables, bitmaps and so on are issues that data recovery labs deal with routinely. They can be dealt with after a hard drive is repaired and an image, or a copy, is made of it. The same is true of solid-state drives; an image could be made, and logical issues worked out from there.

Where solid-state drives differ is how they physically store data and what efforts can be made when the device itself – rather than the file structure or metadata – has problems.

Solid-state memory works with transistors – think tiny little gates that either allow or block the flow of electrons – instead of tiny patches of metal that are magnetized or demagnetized. The transistors are packed into computer chips, and a solid-state drive will employ several chips. When a file is stored on a solid state drive, what typically happens is that the file will be pulled apart, or “striped,” and stored across several chips. To perform data recovery on a failed SSD, it is often necessary to read each chip individually in a custom reader, and then try to figure out how the data is striped. This varies by manufacturer and model, and is proprietary. In effect, it is a form of encryption. This is why data recovery is often impossible for labs that have not invested in considerable SSD research and development and have worked closely with SSD manufacturers. And even labs that specialize in SSDs may have trouble with SSDs from smaller manufacturers or less widely produced models.

SSDs have a lot of advantages – they’re quiet, fast, energy efficient and shock resistant. But it is worth making sure that there is an automatic remote backup running on workplace laptops running SSDs. And it’s worth checking in with data recovery labs to see whether they can recover data from SSDs and, if so, which models they can support in the event of a hardware issue.
Lee's profession is marketing and product development for a rapidly growing data recovery and software development company. His career started with newspaper journalism; after award-winning reporting from Baghdad, he went on to be the speechwriter and communications director for a governor before leading communications and public relations for state agencies. Lee's education is in economics and math. He was a collegiate rower and now races bikes.

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