Stefan Mileschin

Samsung, the World’s leader in Solid State Disk Drives may have inadvertently trimmed their sales. A story on StorageServers yesterday suggests that Samsung’s SSDs “could be wiping data” due to the SSD Controller’s improper functioning of the TRIM command.

The TRIM command allows the Operating System to inform a Solid State Drive which blocks of data are no longer considered in use and can be erased. The Trim command was introduced soon after SSDs started to become an affordable alternative to traditional hard disks. Because low-level operation of SSDs differs significantly from hard drives, the typical way in which operating systems handle operations like deletes and formats resulted in unanticipated progressive performance degradation of write operations on SSDs. Trimming enables the SSD to handle garbage collection overhead, which would otherwise significantly slow down future write operations.

According to StorageServers, an engineer with Algolia claimed to have discovered the bug in the way in which the drive reallocates blocks of data. Instead of zeroing areas which contain previously deleted data as they are supposed to, the drives appear to be deleting 512 byte blocks in “random locations on the drive” resulting in corruption of large file systems and near total erasure of small files. Hope of recovering the data was reported as “a tedious task” at best.

http://www.techeye.net/chips/samsung-ssd-trims-data