Western Digital AAKX Fails After Power Outage

Summer brings us the joys of long days, warm weather, and perfect opportunities to go to the beach. But it also brings us oppressive heat, humidity, and thunderstorms. Lightning strikes occur more frequently in the spring and summer than in any other season. Electrical storms can cause power surges and blackouts. When your power goes out, you usually expect everything to turn back on again as if nothing had happened. (As any readers affected by the Northeast Blackout of 2003 will recall, though, it may take a day or two.) But for this recovery client, everything came back on but their hard drive. The client removed the drive from their PC and attempted to use data recovery software, but could not recover anything. The client came to us for our power outage data recovery services.

Data loss after a power outage isn’t extremely common, but there are many ways it can happen. Most people know the pain of suddenly losing a document or project before they have had a chance to save their most recent changes if the program crashes or the power goes out.

This is logical data loss, meaning it doesn’t involve any physical damage to the storage device. Many programs have automatic recovery capabilities that can help to ameliorate the effects of data loss to varying degrees of success. Some filesystems such as Linux Ext4 and Macintosh HFS+ have journaling capabilities, which can prevent data corruption in the event of a sudden shutdown.

How Power Outages Can Cause Physical Failure

Data storage devices, especially hard disk drives, don’t take kindly to sudden shutdowns. If a storage device loses power without warning, the boot sector can become corrupted. (This is why you’re always supposed to safely eject an external drive or USB thumb drive before unplugging it.) For hard disk drives, there is an added danger.

When you normally shut down a computer or eject an external drive, the computer sends signals to the hard drive to prepare it. If you cut the power without warning, the hard drive’s read/write heads may crash into the platters and cause the drive to fail.

In this power outage data recovery case, the client’s hard drive would not boot up. While the client heard no funny clicking noises coming from the drive, that did not rule out the possibility that their Western Digital hard drive had physically failed as a result of the blackout.

Power Outage Data Recovery

Whenever a hard drive loses power without warning, there is a risk of the drive becoming damaged. Upon evaluating the client’s hard drive, we determined that this had happened to the drive. The read/write heads had not failed completely, but were in degraded condition. Our engineers refer to these kinds of heads as “slow” heads, because their abilities to read and write data quickly have greatly diminished.

Slow heads are often on the verge of failure. Because slow read/write heads cannot perform their duties at a hard drive’s natural pace, the drive will fail to perform even the most basic of tasks in a normal setting. In many cases , these heads must be replaced in our cleanroom. But in some situations, our engineers can talk to a drive with slow heads just by speaking to it at its own pace.

Power Outage Data Recovery Case Study: Western Digital AAKX
Drive Model: Western Digital WD2500AAKX-00U6AA0
Drive Capacity: 250 GB
Operating System: Windows
Situation: Drive failed to boot after power outage, recovery software failed
Type of Data Recovered: Quickbooks, documents, Excel spreadsheets
Binary Read: 46.5%
Gillware Data Recovery Case Rating: 9

This is something our own specialized data recovery tools allow us to do. By skillfully altering the operation parameters of HOMBRE, our data recovery engineers could slow down the read time enough to let the heads read data from the drive’s platters. The read/write heads did not perform perfectly, but after reading 46.5% of the drive’s sectors, our engineers had recovered 99.9% of the user’s files. The vast majority of the user’s critical Quickbooks files, documents, and spreadsheets were completely recovered. Our engineers rated this power outage data recovery case a 9 on our ten-point case rating scale.

Why Gillware Does Not Recommend Data Recovery Software

We generally do not recommend that people with hard drive failures attempt to use data recovery software on their own. There are plenty of software tools out there, many of which are cheap (or free) and easy to use. But we’ve seen far too many recovery cases come to us that would have gone much more smoothly had the client not tried to use software on their own to recover their data. Like with most DIY data recovery methods, these things can do more harm than good.

Software data recovery tools cannot help at all if a hard drive has suffered a mechanical failure. File recovery software cannot fix a failed or failing read/write head. It cannot unjam a stuck spindle motor. It cannot undo platter scratches. Running a physically failed hard drive in order to use recovery software can—and often will—cause even further degradation, resulting in data loss which may be unrecoverable.

Data recovery software can only recover data that has been lost due to logical failure, such as file deletionaccidental reformatting, or filesystem corruption. If the logical issue is not very complex, recovery software will often do its job just fine. If it is a complex logical issue, though, these tools will often fail. And if the software is installed and run on the same drive that has lost data, the mere act of installing and running the software can irreversibly overwrite critical data.

At Gillware Data Recovery, our engineers use HOMBRE, an intelligent, fault-tolerant recovery hardware and software package of our own design, to assist in our data recovery efforts. With these tools, we can move at a hard drive’s own pace, even if its components are in rough shape, and recover our clients’ data from complicated logical data loss situations.

Will Ascenzo
Will Ascenzo

Will is the lead blogger, copywriter, and copy editor for Gillware Data Recovery and Digital Forensics, and a staunch advocate against the abuse of innocent semicolons.

Articles: 213