Surprising facts about disks and fires…
Successful data recovery from a hard drive which has been exposed to a residential, office or industrial fire depends on a number of factors. These include factors such as the level of exposure to the fire. It depends on the level of smoke particle ingress. It depends on whether the label has been burnt or not. It depends on whether the disk is a hard disk drive (HDD) or solid state drive (SSD). And recovery can also depend on how much exposure the disk had to fire suppression agents such as water.
Burnt disk labels – If you have an HDD or SSD damaged by fire, sometimes the biggest challenge can be a burnt label. The reason for this is simple. If you have an HDD with a fire-damaged PCB but is otherwise mechanically sound, using specialised data recovery equipment such as PC-3000 it’s firmware can be emulated and the volume read. However, in order to emulate a disk’s firmware, you need to know the disk family and the model number. Without this firmware information emulation cannot take place. Similarly, if an HDD involved in a fire requires a head-disk assembly (HDA) replacement swap, it’s also imperative to know the model number. HDA swap operations need to use exact-match donor parts. Likewise with an SSD, you might have a fire damaged SSD which could be read using disk emulation. But you need to know the model first. You also need to know what controller chip the disk using. We really wish disk manufacturers would use fire retardant labels…
SSDs will survive a fire better than a HDD – The NAND chips on SSDs can survive temperatures of up to 300 degrees Celsius. (Controller chips are much more sensitive to heat though) In contrast, HDDs exposed to temperatures of over 60 degrees Celsius you will see bit errors start to multiply. Moreover, with HDDs exposed to fire their disk-heads are liable warp and are also liable to make contact with the platters due to excessive heat.
The water damage incurred by sprinkler systems or fire crews can be worse than the damage incurred by the fire itself – This one surprises a lot of people, but water (used for fire suppression purposes) often does more damage to hard disks than the fire itself. Within a very short space of time, micro corrosion sets in on the PCB components (such as diodes, capacitors and tracks) causing short-circuits. These short circuits can prevent a disk from initialising.
Smoke Damage – Electro-mechanical hard disks are hermetically sealed units designed to block out any contaminated air. They use a rubber gasket to secure the seal between the chamber and the lid. Even in polluted industrial environments, this mechanism works well at keeping contaminants out. However, the intense heat of a fire can cause a disk’s rubber gasket to deform or melt paving the way for the ingress of smoke particles. For the disk, this can be catastrophic. Smoke particles on the platters are the equivalent of rocks on a railway track. These particles can accumulate under the disk-heads blocking the read/write signals, scouring the platter surface but can also cause the disk-heads to overheat.
Practical Tips
- Off-site backup provides the best protection against data loss due to fire damage. Even if you think your premises has a low fire risk, it can often be an adjoining premises that’s the source.
- Your server or comms room should have a high-sensitivity smoke detection system (HSSD) smoke detector installed which is regularly tested.
- Try to maintain an off-site inventory of disks inside your systems. A record of disk model numbers can sometimes make the difference between a failed or successful recovery. IT asset management tools like LanSweeper can automate this task.
- If adopting a belt-and-braces approach in mitigating the fire risk to your data, you could consider fire-retardant DAS and NAS solutions from ioSafe. These storage devices running DSM (from Synology) offer protection of your disks from fires up to 840 degrees Celsius for up to 30 minutes. They also offer IP68 water protection – very useful protection from sprinkler systems and over-zealous fire crews.