Your hard drive is playing up - should you stick it in the freezer?

John Leonard takes a look around the data recovery centre at Kroll Ontrack

Your hard drive is playing up. Should you stick it in the freezer?

This long-standing tech tip certainly sounds like a modern myth, but Robin England, senior research and development engineer at data recovery firm Kroll Ontrack insists that, in certain circumstances, it may have merit. In fact, it is one of the few DIY interventions that might be worth a try.

"Some chips in the controllers are temperature-sensitive and if you cool them down they might start working again," England said. "Also there's a mechanical aspect. You've got the alignment of mechanical parts. By cooling them down they might contract and that could help the drive locate the heads. It could work."

England is adamant, however, that those who advocate heating solid state drives (SSDs) as a way of recovering data do not know what they are talking about.

"You're more likely to lose your data than recover it that way," he said.

Every day Kroll Ontrack's data recovery unit in Epsom, Surrey, books in about 25 damaged or defective drives, phones, SANs, arrays and other devices. About 10 per cent of these bear the signs of botched recovery attempts: sealed units being prised open, for example - something that the firm says can drastically reduce recoverability.

Those media that are not physically damaged can usually be recovered using software tools. However, the 70 per cent that are burned, bent, bashed or otherwise compromised need to be carefully dismantled in a dust-free cleanroom, where attempts are made to rebuild the device using parts taken from the huge inventory that the firm maintains.

Flash bang wallop

In recent years more SSDs have been finding their way onto the lab's benches as they have become more popular. During a visit by Computing to the cleanroom, England and his colleagues said that while the prices of SSDs has fallen steadily they have not seen much of an increase in reliability.

"It's getting cheaper and that's what manufacturers are pushing," he said. "They have no interest in a drive that lasts forever. Flash is still an emerging technology."

Because flash drives are relatively new, there can be problems with manufacturing quality, said England. Also, having no moving parts there are fewer warning signs that an SSD is about to fail. Another problem is the wide variety of solid state technologies and standards.

"With every solid state device that comes on it's almost like it's a different data structure, a different standard," said England.

However, England said that most of the data from the majority of devices that end up in his lab can be recovered, even in the case of extreme damage, given enough time to develop the appropriate tools.

The lab is seeing more mobile devices, too. These are mostly sent in by careless consumers afraid of losing family photos rather than business users fearing loss of sensitive data.

"I think a lot of businesses have really got to grips with BYOD and are making sure they have the data backed up regularly. We do see a lot of smartphones that have been run over by a car in the driveway or dropped down the toilet, but it tends to be more home users," England said.

Back it up!

Keep your data regularly backed up and you should not need to pay outfits like Kroll Ontrack to recover it for you. But despite the increasing use of virtualisation and cloud - which make automated backup technically much easier - Paul Le Messurier, programme and operations manager, said there has been little drop in demand.

"We all plan to back up our files but it doesn't always happen," he said. "It's a people problem."

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Your hard drive is playing up - should you stick it in the freezer?

John Leonard takes a look around the data recovery centre at Kroll Ontrack

For enterprises, the creation of a single point of failure as devices are consolidated is at the root of many of the most serious cases, said Le Messurier. For example, if a physical server hosting tens of virtual machines running mission-critical applications falls over and backup services also go down, the result could actually be fatal for the organisation if not recovered quickly.

Virtual machines create a number of difficulties, said England.

"For a start the data is stored on a number of levels, there are a number of software layers that separate the data from the storage device itself," he said. "To piece that back together can be a complex task."

The largest recovery job that England has been involved in was a database with two billion records on a virtual machine.

"This was a real challenge," he said. "It took three months to reconstruct the data."

Encryption can also slow things down. "Some certifying authorities require that there be no access at all to any areas of the drive that might be a security risk," he said. "That means some of the areas we normally access to make a repair are not available to us, so some development work will be necessary."

Kroll sees a number of high-end SANs and RAID arrays pass through its doors, recovery from which can take weeks and will inevitably be very expensive, possibly running into the tens of thousands of pounds.

But many jobs concern the humble tape. With most large organisations still using backup tapes, dealing with legacy infrastructure remains a key activity for Kroll, especially around the requirements of data retention legislation.

"Firms don't know what do with the myriad backup tapes, they don't know what backup software has been used or they want to discontinue using it because it's too expensive to maintain," said Le Messurier, explaining that recovering data from outdated or damaged tapes is still a mainstay as firms struggle to comply with data retention legislation.

"Companies don't know when they will be called upon to supply that data," he said. "This is one of the key things we're coming across with corporates these days."