Samsung SSD TRIMs data

Samsung-SSD-ActivatedSamsung 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.

Samsung SSD models confirmed with the problem are:

  • Samsung MZ7WD480HCGM-00003(SM843TN)
  • Samsung MZ7GE480HMHP-00003(PM853T)
  • Samsung MZ7GE240HMGR-00003(PM853T)
  • Samsung SSD 840 PRO Series
  • Samsung SSD 850 PRO 512GB

Samsung recently issued a firmware update to fix problems with the 840 EVO SSD which exhibited slow read speeds. A new team has been assigned to look into the TRIM data erasure/corruption problem and will be issuing an update shortly.

TechEye Take

Samsung does not like stains like this and will break out the reserves to not only fix the problem but also ensure that it does not re-occur.

We are trying to find out whether any of the affected drives contain any of Samsung’s 3D NAND-Flash devices.  They are not indicated as having any part in the reported problem.

It will be interesting to see whether this will have a positive effect on their competitors ‘share price on Monday’s market open…,