When looking for a data recovery tool, you’ll encounter many products claiming support for SSD drives among other types of media. From the developers’ standpoint, SSD drives are no different from classic, spinning magnetic-type disks. This fact allows manufacturers of data recovery tools claim SSD support without changing a single line of code.
However, this is not the case. Today’s SSD drives are inherently different in how they manage information, in particular in how they manage deleted data.
If you read our article on how Windows manages deleted files, you know that information you delete from classic media is not actually being destroyed. Instead, the files are simply marked as deleted, and any space they used to occupy on the hard disk is advertised as available. This is it; Windows won’t do anything to actually wipe, clear or overwrite sectors that contain information that belongs to deleted files.
It all changed when SSD drives with TRIM support have been introduced. The TRIM command is used to allows an operating system communicate with the hardware (an SSD drive in our case), telling the drive which blocks of data are no longer in use. The SSD drive, in turn, is supposed to wipe those blocks internally in order to gain faster write performance.
TRIM was introduced to avoid the progressive degradation of write performance on SSD drives being filled to near full capacity. Effectively, the TRIM command serves as a garbage collection tool, helping SSDs prevent future slowdowns to write operations.
Do TRIM-enabled SSDs Make Data Recovery Obsolete?
What does this all mean for us? It means you can no longer count on your files staying intact after being deleted. Due to the ongoing use of the TRIM command by the operating system, the empty blocks are likely to be completely erased after a while. Sooner or later, everything you deleted from the SSD disk will be gone forever. With TRIM enabled, once you delete something on a SSD, it’s really gone. Which means So traditional undelete utilities will no longer be effective. Even quickformatting a partition will wipe everything out.
The good news, however, is that TRIM does not really affect the recovery from hard drives that suffered a logical crash such as corrupted file system or broken partition table. You can still use common data recovery tools in order to recover corrupted SSD drives just as easily as magnetic HDDs. However, it is still recommended that you disable TRIM before performing any data recovery job on SSDs.
Disable TRIM When Doing Data Recovery
How do you prevent this from happening, and, more importantly, what should you do to maximize your chances of successful recovery off a SSD drive? You’ll need to disable TRIM as soon as you discover the need to recover information from that disk. Which means ASAP. If you’re reading this and you have data sitting on your SSD waiting to be recovered, disable TRIM right away.
How to Disable TRIM in Windows
There are several ways of doing this. If you’re running Windows 7, you can run the fsutil command from the command line (run cmd.exe in elevated mode to access the console) to check TRIM status and disable TRIM if it’s on. Fsutil is a system tool available in every Windows installation (at least in Windows 7); it’s not something you have to download or install, it’s already available in your system.
fsutil behavior query disabledeletenotify
You’ll receive DisableDeleteNotify = 1 if TRIM is disabled, or DisableDeleteNotify = 0 if TRIM is enabled.
Use the following command to disable TRIM:
fsutil behavior set disabledeletenotify 1
When you’re finished recovering data, use the following to enable TRIM:
fsutil behavior set disabledeletenotify 0
If you’re not using Windows 7, or if you’re not comfortable running command-line tools, you can simply pull that SSD off your PC (make sure to shut down the computer first) and connect it with a USB cord by using a 2.5” enclosure. Done: Windows does not implement TRIM commands over USB. You can now safely perform the recovery with your favorite data recovery tool such as The Undelete.