Water, Water Everywhere
When a hard disk is immersed in water can it just be dried off an re-used? The short answer is "no", so what problems will be caused to a hard drive by flood water, or water from any other source? At first sight a hard disk drive that has been sitting in flood water for 3 weeks looks doomed, but sometimes the data can be recovered so long as the correct procedures are followed and the hardware engineers are adequately skilled.
Hard disks are electro-mechanical precision devices that do not take kindly to being immersed in water. If the water in question is from an overflowing river then the contaminants within the water make the situation even worse.
After 3 days under water you might think that all would be lost.
In this case there were 4 hard disks that had been sitting happily within their host computer systems and working away when the water arrived. Once the clean-up began it was clear that the computer systems had been destroyed, but was there a chance of rescuing the data from these disks?
Quite sensibly the company to whom the hard disks belonged immediately recognised that professional data recovery services would be required. Any attempt to read from the disks would fail and perhaps make matters worse. The hard disks were duly shipped to a UK data recovery company for inspection.
We received a call about 3 weeks after this to see if we thought any data recovery was possible, as the reports from the first company were that the problems were terminal.
The biggest problem we found when examining the disks was not caused by the initial ingress of water and other substances but by steps taken previously to attempt a recovery from the disks before they had arrived at Altirium.
The first hard disk had previously been opened and upon inspecting the inside we found that the upper surface of the upper data platter was undamaged, if still covered in debris. The read/write heads were badly contaminated and would require replacement. Closer inspection then revealed that the platters had been removed from the disk enclosure which meant that the relative alignment between the platters, that is critical to the functionality of the drive, had been lost. This additional problem was going to significantly add to the work involved in the data recovery process.
Looking at the underside of the lower platter we then identified a serious problem. physical damage to the platter had been caused by the drives read/write heads, and visible track marks on the surface that were the result of the hard disk being run without first being thoroughly cleaned.
The result was that the service areas of the disk, where all of the defect management and other system data is stored, were damaged beyond repair and no significant data would be recoverable.
Identical faults were identified in two further hard disk drives that we examined. It was only with the final disk that the air of gloom lifted. Due to extensive damage clearly visible externally to the hard drive, no attempt had been made to apply power, which could have caused the platters to spin as with the previous exhibits. This disk had not been run, and although the internals of the hard disk were heavily contaminated, as were the heads and the platter surfaces, there was only minimal damage to the disk platters. The work would be painstaking, but recovery of data from this final disk would be achievable.
After thorough and careful decontamination of the hard disk casing and replacement of the read/write heads, a 90% recovery of the data was achieved. The recovered data from the hard disk contained 100% of the information required by the customer.
That a hard drive data recovery could be made was a combination of extensive external damage thus preventing any unskilled attempt at accessing data on the hard disk and the skill, diligence and determination of Altirium's data recovery experts. Who, from past experience dealing with such cases, knew that a hard disk that have been exposed to such contamination should never be powered on before a full internal examination of the drive has been made to ensure all critical components were in working order or had been replaced to minimise any risk of further damage, that could turn a potentially working drive into an expensive brick.
Last Updated (Wednesday, 17 June 2009 14:37)