Are hard disk drives damaged by smoke recoverable?

The old saying 'fail to prepare, prepare to fail' is certainly an apt proverb in IT circles.

There are countless ways that business data can be corrupted or lost completely on hard disk drives, but there is little knowledge around the potential damage from smoke.

According to ESET, smoke particles are among the most damaging materials that can get inside a hard disk drive, making it extremely difficult to recover information stored on the drive.

This can be of particular concern for organisations that have suffered fire damage, but ESET asserts smoke damage is often overlooked when it comes to disaster recovery plans.

"Smoke particles look like jagged rocks when viewed through a microscope. They can enter the hard disk drive through the air pressure equalisation hole and bounce across the surface of the disk at high speed," says ESET senior research fellow Nick Fitzgerald.

"This causes scratches and other damage on the surface of the disk where the data is stored. Even with filters inside the drive assembly, the particles can still cause damage. Newer, hermetically-sealed disk drives are protected from smoke particles. However, they may still be subjected to damage from corrosion on the external parts of the disk, such as the drive controller's circuit board, in the event of smoke exposure.

While it's easy to see if a hard disk drive has been exposed to fire or water, FitzGerald says smoke damage can often be invisible and take weeks or even months to manifest, often in subtle ways.

In light of this, ESET has put forward nine steps to recovering smoke-damage hard disk drives:

1. Power down the system. 
2. Discharge static by grounding the computer and the person. 
3. Remove the hard disk drive and clean the exterior with an antistatic, lint-free, microfibre cloth. 
4. Clean the circuit board with an antistatic nylon brush. 
5. If there's a visible layer of smoke residue, gently cover the air pressure equalisation hole with a piece of electrical tape attached so the part visible through the hole is the non-adhesive side. 
6. Moisten the cleaning cloth or brush in a 1:1 mixture of distilled water and isopropyl alcohol so that it's damp but not soaked, and clean the exterior. 
7. Do not remove the electrical tape until the hard disk drive is completely dry. 
8. Once dry, remove the electrical tape and very lightly clean around the air pressure equalisation hole with a dry cloth in a direction away from the hole. Under no circumstances should the hard disk drive be powered on while the air pressure equalisation hole is covered. 
9. The hard disk drive can then be plugged into a computer and valuable data copied from it

According to ESET, following this process may enable the hard disk drive to still be serviceable, especially if it was powered down at the time it was exposed to smoke and cleaned properly afterwards.

"If the data on a damaged hard disk drive is very valuable, it's advisable to contact a professional data recovery service rather than attempting to recover the data in-house and potentially making the data completely and permanently irretrievable," says FitzGerald.

"The failure rate for hard disk drives is 100 per cent eventually, so organisations shouldn't rely exclusively on them to store important information. It's essential to regularly back-up information stored on the computer and take extra care of external hard drives."