Data recovery experts report solid state hard drives can and do fail, and data on these all-silicon drives can be harder to restore than on their magnetic cousins.
Solid state hard drives are fast, are coming down in price and already beat conventional magnetic disks on comparisons of price to
And at least one hard drive file recovery expert finds the new drives are harder to work with than their magnetic cousins.
“We have had a few of them and they are much harder to recover data from,” says Jason Curtis, a Senior Lab Technician at CBL Data Recovery.
Curtis believes wear-levelling algorithms are responsible. These algorithms were developed because solid state disks have a finite life: it is only possible to write to each NAND or NOR gate in a disk a certain number of times before it becomes unusable. Wear-levelling algorithms keep track of which gates have been written to and share the load around to prevent early burnout.
“The algorithms are a bit like RAID: they spread data across different chips,” Curtis says. “Once data is spread over more than four chips in the disk, it gets very hard to recover.”
SSD vendors don’t help either. “The algorithms are proprietary so we have to reverse engineer them,” in any attempt to receiver data. This process that does not always work.
Another data recovery expert, Ari Raymond, Ari Raymond, the Owner and Senior Data Recovery Technician at Total Data Recall, says he has had some success working with flash memory sourced from USB drives.
“We handle USB drives at component level,” he explains. “We pull the memory chip off the board and then read the chips separately. Each drive manufacturer has its own controller and we mimic the controller.”
Raymond has not, however, seen more than a handful of enterprise-class SSDs. Of those he has seen, he says controller damage has been the dominant problem.
“They just were not reading data from the hard drive or had bad solder joins,” he says. The latter problem can sometimes be fixed with special heating equipment that makes it possible to warm solder so that chips can be removed or joins restored.
CBL’s Curtis reports other issues.
“We’ve seen electrical problems,” he says. “You can have surges through them. Lightning strikes, faulty power supplies and faulty connections are other issues. If we can detect the drive, it is usually okay. But physical failures are hard: even the company that made the drive cannot restore data when that happens.”
This was first published in September 2010