The advent of SSDs has brought on a whole new set of data recovery challenges for Clean Rooms across the world, not only because they are complicated devices, but physically working on SSDs is time consuming and complex. Flash recovery is nothing new, but the differences between the 32MB USB sticks of old and the modern day 320GB SSDs of today is huge. Not only are the electronics far more complex, but so is the way the data is written and stored on the NAND memory chips.
In the case above, we received this SSD as it had failed and was no longer recognised. The customer was desperate to get back his MS Office files and his emails.
Initially (as with all flash jobs) we began by carefully analysing the electronics components on the SSD. Naturally this was a delicate and time-consuming process. In addition it was made more difficult as there are a vast number of resistors, capacitors, diodes and so on, that need to be individually checked.
Unfortunately, it looked like the cause of the failure was to do with the controller itself, so our only option was to work on the raw data from the memory chips.
This again was a complex process. The chips on this particular SSD are stacked. This means that a space which would normally be taken up by a single memory chip, was now taken up by two; one soldered on top of the other. This is a method used by manufacturers to essentially double the capacity without having to increase the physical size of the device.
Being a 256GB SSD, this device had sixteen bays of stacked chips, making a total of thirty two chips to work on, each chip being 8GB in capacity (or 16GB per stack).
After a lot of work – both physical and logical – we managed to recover most of the data the customer wanted, so he was delighted.
SSD recovery is challenging and complex, and there are many factors which can influence the possibility of recovery of data from these devices. Some controllers scramble the data as it it written to the memory chips, some encrypt it, and some do both! Throw in the possibility that any number of electronics components on the device can go bad, and you will quickly find yourself in a very murky place.