When a hard drive comes to our data recovery lab here at Gillware after spending some time in another data recovery company’s lab, it’s usually for one of two reasons. Commonly, the other data recovery company had charged the drive’s owner an amount of money for their services far in excess of what the data was worth. In other cases, the drive had sustained damage beyond the scope of the other lab’s tools and techniques. In this hard drive platter damage recovery case, the client came to us after another data recovery lab had pronounced their data unrecoverable.

Spoiler alert: [highlight_sc bg_color=#000000 text_color=#000000 border_color=]We recovered their data.[/highlight_sc]

Western Digital hard drive recovery


Hard Drive Platter Damage Recovery Case Study: Western Digital WD1001FALS
Drive Model: Western Digital WD1001FALS-40Y6A0
Drive Capacity: 1 TB
Operating System: Mac OSX
Situation: Drive had severe platter damage; other data recovery company pronounced it “unrecoverable”
Type of Data Recovered: Financial and office documents
Binary Read: 42.9%
Gillware Data Recovery Case Rating: 7


Hard Drive Platter Damage

We can never labor the point often enough—the guts of your hard drive are extremely sensitive, and the margins for error are razor-thin. And so, of course, when things go wrong, the situation can look pretty grim.

All of your data lives on the shiny, pristine surfaces of the hard disk platters inside your drive. These platters are made out of either aluminum or glass; the thin layers of ferromagnetic alloys coating their surfaces contain all of the zeroes and ones that comprise your data. One side of a single platter can hold hundreds of gigabytes of data. And your hard drive’s read/write heads are solely responsible for reading all this data.

The read/write heads hover only a few nanometers apart from the surfaces of the platters. A single nanometer can fit about ten hydrogen atoms end-to-end! The distance of just a few nanometers is so incredibly small that to the naked eye, and even under a microscope, the heads and platters look like they’re touching each other. But the heads and platters must never touch.

How bad is it when the heads and platters touch? While not quite “crossing the streams” bad… your data won’t fare very well. If the heads collide with the platter surfaces, they can gouge out chunks of the thin coating holding your data. If the platters continue to spin with the heads pressing down on them, the heads can create concentric rings in the platters. We call this “rotational scoring”.

We’ve seen plenty of hard drives come to us after competing labs told their client that no data recovery was possible due to “a round scratch on the platters” or “severe visible media damage”. But with the right tools, data recovery can still be possible.

Hard Drive Platter Damage Recovery and Results

Our cleanroom data recovery expert Charles handled this data recovery case. There were several platters inside this Western Digital hard drive. Of the platters, only the surfaces of the top platter had any visible damage to it.

Every single scratch and concentric ring on a damaged hard drive platter signifies a part of the platter that no longer has any data on it. Whatever used to live in those parts of the disk now exists as a fine powder. And there’s no getting it back. If your firmware sectors or the critical data you needed recovered lived on those now-uninhabitable zones of the platters, it’s curtains for your data. Fortunately, the firmware zone typically lives on a hard drive’s bottommost platter, so in this case, this drive’s firmware was safe.

After burnishing the drive’s platters to make sure all debris on the platters was gone, Charles replaced the drive’s crashed read/write heads. Then came the moment of truth: seeing whether we could salvage the client’s important data from the drive.

Salvaging data from a hard drive with scratched and scored platters is tricky business, even after burnishing the platters. Data recovery depends on where the damage is, and whether or not key filesystem metadata or the client’s critical files have been severely affected.

After managing to read 42.9% of the sectors on the drive, we had picked up 99% of the directory structure and file definitions on the drive. We salvaged everything we could get from the repaired drive, fully recovering 76% of the files in total. A far cry from the zero percent the competing lab managed to recover!

And, fortunately for the client, their most critical financial data was within that 76%. This data recovery case was a success.

Rotational Scoring: A Data Recovery Death Sentence No More

Rotational scoring on hard drive platterRotational scoring is still a big problem for data recovery labs. Even at Gillware, sometimes rotational scoring can just be too severe. Of course, when the client’s critical data has been ground into powder, there’s nothing anybody can do to retrieve it short of reversing the flow of time itself.

But that wasn’t the issue that made rotational scoring so devastating for data recovery labs—and their clients. The big problem with rotational scoring that continues to vex other labs to this day isn’t just the empty spots on the platters. It’s what happens to the metallic coating that used to live in those spots.

The ground-up metal dust created by hard drive platter damage would embed itself on the platters, turning their smooth surfaces lumpy and bumpy, and giving any set of healthy donor read/write heads a big target to hit. And so when a data recovery engineer would replace the drive’s failed heads, the new heads would crash into the debris almost immediately.

Until Gillware developed its own tools to deal with scratched hard drive platters, no data recovery business had the means to reliably clean off this debris and smooth out the surfaces of damaged platters. Recovery engineers would simply pronounce these drives dead on arrival. And that would be the end of it, even if the client’s most important data was still intact on the platters..

Thanks to Gillware’s innovations, rotational scoring no longer necessarily means the end of the world for your critical files. Despite what the other labs might say, there’s still hope for your critical data. So save yourself the time and grief and send your failed hard drive to us first!