A2zDataRecovery

Solid State Drives (SSD) have no moving parts and deliver improved response times while working with computers. However, some performance problems can arise if data is deleted from SSD and new data is to be written to the deleted areas. Unlike mechanical drives, which simply overwrites new data over old data, SSD will need to purge the old data before writing new. That can degrade performance.

Before we look at how this problem is solved, let us take a look at the deletion scenario in mechanical drives. These drives keep pointers to all data on the drive in an indexer. When you delete a file, only the indexer entry is removed; the file itself remains intact till some new data is written to that file's area. In such a situation, data recovery from deleted files is possible so long as the old data has not been overwritten.

Now comes the improved SSD scenario. To speed up performance, a new command TRIM was introduced to deal with SSD deletions (and other tasks). TRIM will remove not only the indexer entry but also the data contained in the file. As a result, the SSD can now write new data to that area without having first to purge it of old data.

What this means for data recovery is that data deleted from TRIM SSDs is no more recoverable. It is gone for ever.

Read the story at: http://techgage.com/article/too_trim_when_ssd_data_recovery_is_impossible/