So generalizing, the data will be erased when the SSD is powered on and idle. Actual erasure of TRIMMED blocks may take some time, and it’s typically something a SSD does when being idle. There are more reasons that may prevent data from being TRIMMED. Some drives may NOT use the RZAT or Deterministic TRIM (DRAT) mechanism (rare IMO but non the less) and may return actual data as long as it hasn’t been actually erased. If files are lost due to some kind of file system corruption, then no TRIM command is issued.Īlso, the interface you used to connect a drive to the PC may be incapable of relaying these TRIM commands so the command never reaches the drive. So when you delete a file or format a drive, the OS will send a TRIM command. You could say a TRIM command is sent when the deletion is intentional. In many cases it may not or it may not reach the drive. So we see key is, IF a TRIM command is send to the SSD. Reality is that they do not contain ANY meaningful data and are therefor beyond repair. However you’ll soon find that they’re ‘corrupt’ at least that’s what photo viewers and editors may suggest. Only trouble is, that when it copies that data to a new file, it’s only reading zeros.įor a moment yo may feel relieved seeing your files are recovered. With that file system entry Recuva has everything it needs to determine the actual disk space that was assigned to the file before the deletion. And this information can then be detected by Recuva. This is called ‘Deterministic Read Zero after TRIM’ (RZAT).Īs you may know, in many cases the file system entry may be available after file deletion for a while. If the contents of the sectors are requested (in our case by Recuva) the drive returns zeros. In 9 out of 10 cases (not exact number, but to make the point) the drive will immediately remove these sectors from let’s call it ‘user addressable space’. Due to the way an SSD works, it has a constant need for free ‘space’ that it can erase so it’s ready for new data, but I won’t be going into that now. By means of the TRIM command it let’s the drive know that the sectors associated with the deleted file aren’t needed anymore. This can be explained by the operating system, when you delete data will send a TRIM command to the SSD. What happens when you delete a file from a SSD? So even though Recuva and other file recovery software appear to be successful in recovering deleted data from an SSD, these files are useless in 99% of the cases. Since this file was deleted from an SSD, this byte value is zero (most likely). This means the file is filled with one byte value repeating over and over, so no actual meaningful data. We can now tell the entropy for the file is 0.00 bits/byte. I want to determine the entropy of the data inside the file. I use my JPEG-Repair software to diagnose the files. I ask him to send me some of the recovered photos. My hypothesis is the files contain only zeros. When you do however try, make sure to install/run Recuva from a different drive and to save the files you’re recovering to a different drive too. Back to the caseĪnyway, since Recuva is free, it’s always worth a try. Problem is that Google Search can’t detect the level of BS so these pages score good. WonderShare (RecoverIt), Nucleus Technologies, Stellar and CleverFiles (DiskDrill) are some examples of that. They’re trying to sell to you, and they sell BS. It all comes down to end user file recovery and undelete software not being able to do anything special when it comes to recovering data from an SSD. In the remaining case, any other decent file recovery software would have been able to help to. They’ll vaguely suggest their software can help. File recovery scammers that promise SSD undeleteĪlmost every manufacturer has a or often multiple ‘honey-pot pages’ on which they try to score on search phrases like SSD and undelete or recover. The major contributing factor is the fact that the files were deleted from an SSD. Any other file recovery software, even the most expensive, would have run into this exact same problem. Can you spot it? I can tell you it is not about Recuva. There’s ONE major contributing factor in this case. “I used Recuva to recover a good chunk of my pictures that were deleted but it seems that even though the file was recovered I can’t view its contents? Any program that helps with this? They were on an SSD if that helps.” Case study, Story goes like: Accidentally deleted some pictures.
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