Recovering and deleting data from SSDs

The latest generation of laptops and hybrid devices use solid state disks to boost performance and speed up the time it takes for the operating system to boot. In this guest blog post, Robert Winter from Kroll Ontrack writes about some of the challenges on attempting to recover data from a damaged SSD.


When choosing a storage media type companies should understand how this decision can affect the ease of retrieving data when there is a data loss.

A lot of businesses are investing in Solid State Drives (SSDs) to leverage its numerous benefits, but users beware. Although SSDs are more robust than traditional hard drives (HDDs), data loss can still occur – and in the event of a data loss, it’s also more complex to recover the data.

Unlike HDDs, SSDs store data in memory chips which have no moving parts, eliminating hardware damage like head crashes or motor defects. Yet, data loss can occur with SSD storage devices because the flash chips are susceptible to physical damage and the way data is stored is complex. SSDs are also exposed to the usual traditional data loss events such as human error, computer viruses, natural disasters, and software/programme corruption.

Recovering data from the common sources of SSD failures requires expertise in overcoming technical challenges that are unique to SSD and flash technology, such as decoding complex SSD data structures, specialised controller chips and numerous other SSD specific issues.  Data is stored on SSD dynamically, and this complexity makes data recovery highly specialised and time consuming. Also a single SSD memory structure can be as complex as an enterprise RAID (redundant array of independent disks) with eight, 16 or even 32 drives!

Only a handful of data recovery experts have data reconstruction programmes in place to identify, separate and reassemble SSD memory so that data can be extracted and achieve high quality results.  At Kroll Ontrack the recovery process involves the following actions:

  • Accessing and reading the data at chip level
  • Overcoming any encryption
  • Rebuilding data striping (much like RAID)
  • Overcoming any file system problems such as corruption or parts missing

The time it takes for Kroll Ontrack to recover data from an SSD is difficult to determine, because the recovery time is dependent on factors including the extent of data loss and the effort required to decode the data from the particular SSD in the device- which is the biggest challenges in the recovery process for SSD.  The way data is configured also varies greatly between manufacturer and models of SSD.  Each model requires Kroll Ontrack to work-out the configuration before data decoding can begin.  In most cases this is done with no help from the manufacturers.

Performing secure data disk sanitisation techniques on SSDs is equally tricky since it’s difficult to specify the exact location of where the data is stored to overwrite it.  Therefore, the best way to permanently destroy the data is through physical media destruction.  This typically involves shredding the media into small pieces so not a single chip escapes destruction. If the shredding process misses a chip, it’s still possible to recover data from it, so care needs to be taken to destroy everything.

SSDs are durable and it’s difficult to assess their lifespan because they vary depending on the manufacturer. To get an idea of how long a solid state-drive will last in application, the following calculations can be used to determine its life span:

It should be noted that these calculations are valid only for products that use either dynamic or static wearing levelling. Use the solid-state memory component specifications for products that do not use wear levelling.

There are various things a user can do to attempt to maximise its lifespan. The best way to find out the right methods is to look at reliable chat rooms and manufacturer recommendations here too.

SSD is a new technology and very few people have learned enough about it to expertly navigate through its RAID and the SSD layers and successfully find data when there’s a failure. Best practice is that before choosing to use it, contact a data recovery specialist for more information about the impact on data recovery for the specific environment and technologies you are investigating.

Robert Winter is responsible for all operations within the area of disaster recovery in the Kroll Ontrack labs, based at the UK headquarters in Epsom.