Be afraid, be very afraid

Robert Winter has made a list of common data nightmares in honour of Halloween

There are many things to be afraid of when it comes to customer data, not least the botched data recovery. Often, when we receive media to recover data from, we aren't the first to make an attempt.

Ill-informed, poorly performed recovery attempts drastically reduce the chances of a successful recovery. 'Cowboy' recovery attempts can cause additional damage.

A recent example is a hard drive that had suffered a physical internal failure. In opening the disk to diagnose the problem the technician caused irreparable damage, accidentally scratching the disk's platters. In my view, that was a real butcher's job!

And then there is the virtualised SAN cobweb. The rise in popularity of NAS and SAN devices has added a layer of complexity to many recoveries. Each brand of these self-contained storage devices uses its own proprietary file system needing bespoke recovery techniques.

Add a pinch of virtualisation and dynamic RAID into the mix and you have a bubbling cauldron of complexity. In the case of data loss on these systems, the owners of the data often don't know which part of the mix has malfunctioned.

Piecing together data from overlapping technologies can be a job that makes the blood run cold.

And what about the mysterious case of the invisible encryption? External hard disks aimed at consumers are increasingly sold with encryption built in. Many people coming to us to get their prized family photos back from their faulty external disk are surprised to hear their disk is encrypted.

The only way an encrypted disk can be recovered is by supplying the password to the engineers. Another encryption-related horror is caused simply by encrypting a disk and then forgetting the password: the result is permanent data loss.

So encryption is a Jekyll-and-Hyde tool from a data management viewpoint. The one process has two sides – it can be a valuable ally against data breach, yet the mortal enemy of a successful recovery.

And what if you have an abusive owner of the data? The massive success of smartphones and tablets has led to an increase in people treating their laptops like more portable devices. Casually walking around with a laptop while it's running, for example, can make your disk about as useful as a Halloween pumpkin.

Traditional spinning disks, unlike the solid state storage found in some portable devices, are very sensitive to movement. A little jolt while the disk is reading or writing can lead to physical damage to the disk and permanent data loss.

The damage may also take time to appear as a damaged disk head drags itself across the platters and the debris from the head crash also builds up and causes incremental damage and eventual disk failure.

So if you've dropped a laptop containing the only version of some extremely important information, back it up immediately, don't assume the disk is OK.

Moreover, when these abusive owners aren't waving their machines around in public, they are at their desks – perhaps drinking coffee.

The common untrained response to a coffee spill appears to be to leave the machine running to see if enough coffee has been deployed to short out the electronics. In fact, the device should be switched off immediately to minimise the damage.

If your customer is using a complicated web of technologies, make sure they understand the implications for data recovery, and that their backups are running as they should. And ask if the files they are storing warrant full disk encryption.

Kroll Ontrack is also running a DataNightmares competition in honour of Halloween.

Robert Winter is chief engineer at Kroll Ontrack