Difference between revisions of "Data Recovery From a Failing Hard Drive"

Latest revision as of 16:25, 15 March 2021

Data on a hard drive may be inaccessible due to physical/mechanical failure, which is different from logical errors on the disk. This article relates to a drive that is physically or mechanically failing. You have a last chance to recover data before the drive fails completely, making the data inaccessible without actually opening the drive.

Logical Failure versus Physical Failure

Logical Hard Drive Failure can occur making it difficult to access your data. Logical disk errors describe problems reading data from a drive that is mechanically fully functional. Data recovery software addresses ways to retrieve data from drives with logical errors. NEARLY ALL DATA RECOVERY SOFTWARE is for drives with logical errors, not physical or mechanical errors and such software typically inappropriate from data recovery from physically damaged drives. In some cases, use of data recovery software may result in you losing data you could have retrieved by other means.

A drive that has any kind of physical damage is far more difficult to recover data from. In many cases, a drive failure is cascading, typically beginning with subtle errors on the drive until increasing exponentially until the drive is a brick. Sometimes the subtle errors go unnoticed and by the time cascading failure becomes evident, it is too late to retrieve most of your data short of mechanical service.

Causes of Physical Drive Failure

• Physical Impact (dropping, or an impact to the drive)
• Excessive Heat (not well ventilated, overheat, external heat exposure)
• Electric Failure (motor)
• Electronic Failure (board, chip)
• Mechanical Failure (bearings, platter surface, contamination)

Any mechanical failure of the disk, or physical damage inflicted to it will almost certainly cause attendant software problems, generally due to bad sectors. Data I/O performance can be negatively impacted by drive bearings causing the platters spinning up slowly or rotating at an incorrect speed.

Stuck Read Heads

Sometimes the heads stick to the platter causing the drive to lock up. If this is the case hitting the hard drive can knock the heads free. This is a temporary fix and should only be used to recover the data. Put your ear to the drive while trying to boot or simply access data. If you can hear servo read head movement then do not attempt this. If the drive is spinning you will hear it turning. Some drives are louder than others.

Head Crash

The computer was banged or suffered impact while the hard drive was in read/write active (the heads were not parked). A head crash can damage both to the read heads and the surface of the platter. It is rare that there is surface only damage. Even if the damage is surface only, and those bad blocks can be marked by the operating system so the drive can continue in use, the data should be recovered and the drive replaced immediately. Such a drive will inevitably fail. The read write heads can also become misaligned as the result of a physical impact.

Electronic / Board / Chip Malfunction

If a control chip on the board has failed, or there is another problem with the electronics on the board, sometimes that board can be replaced with an identical board, thus repairing the defect with the hard drive as a unit, and allowing full functionality including data access. This has been accomplished but is hit and miss largely due to undocumented differences in hard drive boards designated by the same model and series.

Low Temperature Data Retrieval

Freeze the Hard Drive

Some hard drives respond to reduced temperature conditions, making them temporarily functional for the purpose of data retrieval. Engineers have placed drives in a freezer.

1. Remove the hard drive from the computer.
2. Place the hard drive inside of a good quality zip top freezer bag.
3. Place the wrapped hard drive inside of ANOTHER zip top freezer bag.
4. Place the double wrapped hard drive in the coldest part of your freezer.
5. Leave the hard drive in the freezer for 12 hours at least.
6. Once very chilled, install the hard drive in your computer and start pulling off data. Begin with the most valuable data.
7. At some point, the hard drive will fail again. When it does, mark the last successfully copied data, pull out the hard drive, double wrap it again and stick it in the Chill Chest for another 12 hours.
8. You may need to do this a number of times to get all the data you want, or until the hard drive stops working completely.

This procedure ref: source

Review: I believe the risk here is the cold hard drive placed back in the computer will start to collect moisture, in the form of condensation, that could cause water to drip inside of your computer!

Theory: Perhaps it would be best to place the harddrive in a freezer inside a USB enclosure, and after 12 hours connect to your PC via the cable extending from inside the freezer, through the door seal, and outside to your PC. the bag will have a breach in the seal where the cable protrudes so this will have to be sealed with silicone. Try recovering data while the drive remains in the freezer via the USB interface.

Counter Point: Hydro dynamic bearings can't be un-frozen when they blow their seals. This only worked on older ball bearing drives. A hard drive may also fail when the ferrous media layer flakes off the glass platter. Freezing a drive with this problem will not work.

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