Once the data has been cloned, technicians can start recovering files. Even if the directory – the part that tells the computer where all the files are – has been damaged, it’s possible to do a signature search, looking for distinctive header information that tells the technicians where particular file types are.
After a successfully recovery – which typically happens in two or three days – the data is loaded onto a new portable disk and sent back to its owner.
Common disk disasters
The most common physical trauma that a hard disk can suffer from is what the technicians at Kroll Ontrack call a head slap, where the read/write heads are knocked onto the surface of the disk platters.
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It can cause huge problems; since it’s only the surface of the disk that records the data, scraping this coating off means that the information in that section of the disk is probably lost, and if data vital to the operation of your drive or operating system is – or rather was – stored there, you’re in trouble.
What’s more, the dust from the scraped-off surface can further interfere with the hard disk’s operation, and in disks that have multiple platters to increase their capacities, this can be a serious problem.
There’s another horror to contend with. While most of the platters in desktop (3.5-inch) drives are metal, laptop drives (2.5-inch) usually have platters made from glass. Though it’s incredibly tough, it can shatter; both this and the head slap are normally caused by rough handling.
But though disks are finely-engineered things, they can withstand quite dramatic encounters. Though it makes their job that bit harder, data recovery specialist such as Kroll Ontrack can resurrect data from hard disks that have suffered from fire or flood.
Even if the hard disk itself is in good condition, however, there could be problems with the data it holds.
One of the most common reasons people send their disks to Kroll Ontrack is because they have reformatted a drive without realising that there’s essential information on there.
While it doesn’t have the facilities to resurrect data from a drive that has been zeroed out – had information rewritten over every sector – most people don’t do this when erasing hard disks, so Kroll Ontrack can simply ignore the missing directory that gets trashed during a standard format and examine the contents of the disk sector by sector.
Take care of your data
- Be gentle with your computers; physical trauma can damage them in ways that can be difficult or impossible to correct. Allow a laptop to shut down or sleep fully before stuffing it in your bag, for example.
- Back up! But remember that your backup device could fail too. There’s nothing inherently safer about a backup drive compared to the drive inside your Mac; you’re just trying to reduce your chances of a physical drive crash. Ideally, back up multiple times to multiple different media, and remember that offsite backup helps guard against local catastrophes such as fire or flood.
- Protect your disks from strong sources of magnetism. While most domestic sources are unlikely to interfere with the data recorded magnetically on a hard disk’s platters, there’s no reason to be cavalier.
- If you suspect there’s a problem, act quickly. Don’t be afraid to ditch a poorly hard disk – untypical ticking noises can be a good indicator of a failing drive – and restore from a backup; it could be expensive, sure, but it’ll be cheaper than trying to recover your data. Unless you’re confident that you know what you’re doing, you could make things worse, resulting in an even more expensive repair.
- If you do take your drive to a data recovery firm, give them the whole computer or external drive; let them worry about getting at the hard disk. And don’t follow the example of some of Kroll Ontrack’s customers by hacking out the individual platters and mailing them in a Jiffy bag!