How often do you accidentally or thoughtlessly remove some necessary information from your computer? Or – with your brains on autopilot – clean the Trash bin? And furthermore, format the hard drive? We have all been there – not once, not twice, but many times. Do you remember how vigorously you’ve regretted it (or the fact that humanity has not yet invented the time machine)?
Half the trouble if such accident happened with the hard disk drive (HDD). Due to its design peculiarities, the data can be restored relatively easy. On the other hand, solid-state drives (SSD) don’t have moving parts and besides, are built in an entirely different manner compared with the rotating discs.
On the one hand, the nature of your interest regarding data restoration on SSD may be provoked by the question “Can someone recover my data from an SSD on a computer that I am selling or giving away?” Then, you are actually interested in the secure erase.
If you simply delete files from SSD and do not perform other operations after that, the data can be restored at least partially. The thing is, the solid-state drive does not overwrite or delete the existing sector with files immediately. Instead, it writes new information to another location and simply changes the pointer to the new version leaving the old one active for some time. The previous version can be erased with time, or it may not. As a result, even the data that you think was deleted can still be present and available on the SSD.
The most reliable way to safely (however, not reliably, unfortunately) wipe the entire SSD is through the ATA Secure Erase command.
Another approach – to use full disk encryption. To do this, ensure that the whole file system on the disk is encrypted from the very beginning (for example, Truecrypt or BitLocker). When you want to disinfect the disk, blow out all the crypto keys and erase them safely, and then wipe out the disk as best as possible. This can be a smart solution, although it can also be linked to the ATA Secure Erase for better security.
Recover files from formatted SSD
The other side of the “data recovery from SSD” coin is the restoration of unintentionally lost files after disk formatting or failure. And that’s where a user might experience a lot of trouble.
The thing is, one of the distinctive SSD’s features is the wear leveling firmware meant to prolong its service life. It has a trim command (aka TRIM), which is used by the operating system to tell SSD that some files are not in use anymore after you delete them.
When it comes to formatting, the firmware immediately starts to erase data and blocks of space marked as ‘No longer in use.’ This makes the recovery of more than random data bits merely possible in just a few seconds and guarantees its full inaccessibility after a few minutes. If this is the case, even the most powerful recovery software would not be able to help you to restore lost files.
Therefore, try not to format SSD accidentally or until you are 110% sure about that. And set up regular backup, no arguing about that!