12.16.09
Frozen hard drive trick - yes, it really works
Many people are suspicious of the reported trick of freezing a hard drive in a last ditch effort to recover it. Freezing a hard drive to recover data really can work. I don’t know why it works, but I have used it successfully on a disk that would not boot and I can tell you that heat is absolutely an enemy of hard drives. In a nutshell this is how it is done:
You remove the dead or clicking hard drive from the machine. You obtain a second hard drive of equal size or larger. Once frozen you restart the hard drive and quickly copy off all your important data or use dd, ghost, or some other tool to copy all the data over to the second hard drive. You might also hear about using tools like SpinRite to try to repair the damaged drive to get it to a state where it will work under normal or non-frozen circumstances. I prefer to consider the drive damaged goods and get all the information off it and then retire the drive.
There are some important things to know in order to freeze a drive for recovery:
- You need to keep moisture away from the hard drive. Seal the hard drive in an antistatic bag. Use a dessicant in the bag if you have one. You want to keep moisture away from the drive as much as possible. Seal the antistatic bag inside one or two other plastic bags reducing the amount of trapped air as much as possible.
- The drive has to freeze a long time. This is not an instant process. The drive needs to be really cold. Leaving it in the freezer for a 24 hours or more to get the drive chilled completely is a good practice.
- You have a limited amount of time to recover the disk becuase it will warm up fast. Really fast.
- If you need more time, you can buy dry ice at a grocery store and put the drive and dry ice inside a cooler. This is what I do when I recover with some of the linux-based dd tools because they take so long to run - on the order of days for a really big drive.
On new hard drives larger than 350 GB I try to make sure the drives have additional cooling installed. Extra fans or heat sinks to cool them down. I also like to do an initial format of the hard drive and let it warm up, copying some data to and from it to warm it up to “burn in the drive”, before finally formatting it. I do this under the theory that once warmed up the platter sizes are probably different from their cold size and that there is probably a point where the warmed up drive will not get any hotter unless it is under stress. Testing the hard drive before putting it into use also gives it a chance to fail or throw SMART errors before you put anything important on it.
You can freeze a hard drive to make a final try at recovering it but you need to work fast to keep the drive cold and dry. Sometimes a dead drive is truly dead and if it contains critical data or programs it must be sent to professionals to try advanced recovery steps.