Disaster Recovery Group engineers have a saying “If data recovery software can recover your data, you really did not need data recovery services”.

Data Recovery Software: Distributers are vying for your time and money by offering their software packages as an all-in-one data recovery solution.  In most cases of viral infection or limited corruption the software process appears valid.  However for those with physical issues with their hard disk drive the time spent “trying” to recover the data may actually be substantially more destructive to the recovery process and can reduce the data recovery results of a specialist once you have decided to stop your attempts.  If there is clicking and or banging sounds emanating from the drive chances are great that software will not even see a device online or if accessible still can cause additional platter damages by allowing the unit to beat it self up.  The audible sound is the actual head assembly throwing itself across the platters looking or seeking for a signal to lock onto.  The physical stops put in place within the hard disk cavity prevent the heads in these scenarios to come off the media, clamp the heads together and snapping the gimble flexors in-between the head assembly arms and the actual heads as they are reintroduced onto the media.  Think of pinching two fingers on a piece of paper, sliding that paper out and trying to get the paper in-between your fingers again without making a gap.  We have seen many customer drives with broken stops that allowed the heads to do this and the media is damaged in a catastrophic fashion preventing any data recovery options.

Board swapping:  For today’s drives this is highly dangerous.  Most hard disk drive manufacturers equip their products with firmware located on the media within the hard disk cavity and embedded in a ROM on the circuit board.  Many engineering changes within the manufacturing process of a disk product line represent new revisions for that product to increase its reliability and performance.  In some cases we found the internals of a drive to be completely different then the others within the exact same model sequence.  Some cases also showed that the firmware could also be overwritten.  During power up sequences the drive performs a self check and will notice a discrepancy match with the board and hard disk cavity.  Then an erase command is performed on the firmware thinking a set of instructions is going to be written rendering the hard disk cavity useless.  Ten years ago, board swaps were common and reliable as the firmware was only located on the board whereas today’s drives utilize a lock and key style configuration.  The reasoning behind these matched sets are as more powerful electronic components are embedded in a hard disk these can be fine tuned to make ever increasing performance and reliability gains.

Microwave/Oven/Refrigerator/Freezer:  Customers still ask about these remedies so they must be addressed.  DO NOT USE THEM for anything other then storing or cooking your food.  Using a microwave on a hard disk drive can cause damage or injury to yourself and the appliance and will destroy the hard disk.  The oven, refrigerator and freezer are not used by any data recovery company but by “shade tree mechanics” when the hard disk drives developed stiction many years ago.  In the 1980’s and 1990’s hard disk manufacturers used media with properties that would deteriorate from the immense hot cold and cold cycles that a hard disk generates during usage.  When the unit was powered off the physical heads would literally latch or gel block to the media surface.  The torque from the motor was not strong enough to overcome this and would not allow the unit to spin up.  Heating or cooling the unit may have allowed expansion or contraction of the head/media to break it loose.  Cooling always produces precipitation and those water molecules are evident within the cavity and could initiate a physical head crash since it still is debris.  Today’s hard disk drives have laser etching and the media surface is now much more reliable.  Disaster Recovery Group data recovery engineers have not seen stiction since the late 1990’s and very early 2000 so these processes however effective were at that time are now moot.

Opening the Hard Disk Drive Cavity:  Besides the fact that the average drive has clearly stated instructions from the manufacturers regarding the cavity “Product warranty will be void if seal, label, cover or screws is removed or damaged” a few customers will still venture out in their recovery attempts.  Clean rooms rated as Class 100 have no more than 100 particles larger than 0.5 microns in any given cubic foot of air and the normal air one breathes is close to 100,000 particles in that same measurement.  Hard disk drive heads float on an  Air Bearing, roughly a few micro inches above the media’s surface. A human hair is approximately 100 micro inches in diameter to?illustrate the minute lift generated needed to accomplish this effect.  The air outside of a clean room is 1000 times more contaminated and those particles will come to rest on the media surface as the cavity is opened.  As the head comes up to speed and hits those particles the head chatters and gouges/scratches the media surface resulting in permanent data loss.

If the data you need is valuable or irreplaceable on your failed hard disk drive your best method is contacting a Data Recovery specialist like Disaster Recovery Group.  We offer free evaluations and a No Data = No Charge policy with all costs given up front with a guarantee that you will only be billed exactly what was quoted during the free evaluation.

The term RAID is an acronym in the hard disk drive data computer storage venue as Redundant Array of Independent Disks or Drives.  Another commonly used variation for this term is Redundant Array of Inexpensive Drives.

The premise for having a RAID configured to a server, workstation, stand alone computer or network is reliability and fault tolerance.  Hard disk drives have a finite life span and the chances for failure average approximately 3-5 years per the manufacturers estimations.  For this reason corporations, universities, government agencies and other individuals who require limited or no down time will implement a RAID onto their IT network servers or workstation computers.

There are several levels of RAID configurations being RAID 0 through RAID 6 and within those levels are a number of practical applications for a more secured manner of data storage. Within these levels administrators can increase fault tolerance, reliability and/or access speed.

Mirroring:  Imaging identical data onto each of the (2+) hard disk drives.

Parity:  Bits added that is a mathematical algorithym generated by the physical data residing within the sector written also known as Error Correcting Code or ECC

Striped:  Partial data written to each (2+) hard disk drive making it as a whole.

Striped with Error Correcting:  Partial data with parity written to each (3+) hard disk drives making it as a whole.

RAID 0:  This configuration sustains the fastest data throughput however the security of data during a failure is always at risk.  The data is striped onto two (2) or more hard disk drives in small packets without and parity and in the event of even a single drive failure the system can not access the data.  (0) Data storage configuration example: All drives should be either identical in regards to sector count and/or physical configuration of heads and tracks.  Mismatched capacity drives may work but would be limited to the smallest hard disk in that configuration and is always limited on the RAID software or hardware requirements.  Add the total capacity of all drives together.

RAID 1:  Also known as mirrorring.  All hard disk drives will be written to during any writes identically.  The system is accesible for as long as atleast one (1) drive remains operable.   (0) Data storage configuration example: All drives must be either identical in regards to sector count and/or physical configuration of heads and tracks based on the RAID software or hardware requirements.

RAID 3 and RAID 4 :  This configuration is identical with a RAID 0 as the data is striped onto three (3) or more hard disk drives in small packets but has a single drive dedicated to storing parity bits for ECC and redundancy.  If a data drive fails the system is rendered inoperable til a rebuild is performed, however if the parity drive has failed the RAID is still operational.  For any single drive failure the system can recover itself after the rebuild of the data on the failed or lost hard disk drive.   (0) Data storage configuration example: All drives should be either identical in regards to sector count and/or physical configuration of heads and tracks.  Mismatched capacity drives may work but would be limited to the smallest hard disk in that configuration and is always limited on the RAID software or hardware requirements.  Add the total capacity of all drives together minus the one (1) Parity drive.

RAID 5:  This configuration is most commonly used with computer professionals and is similair to a RAID 3 or RAID 4 as the data is striped onto three (3) or more hard disk drives in small packets but there is NO dedicated drive to storing parity bits for ECC as this configuration has a revolving parity.  If any single drive fails the system is still operational.  The system can recover itself and rebuild the data from the failed or lost hard disk drive onto its new replacement and can be done as a “hot swap” if the system has that ability.   (0)  Data storage configuration example: All drives should be either identical in regards to sector count and/or physical configuration of heads and tracks.  Mismatched capacity drives may work but would be limited to the smallest hard disk in that configuration and is always limited on the RAID software or hardware requirements.   Add the total capacity of all drives together minus one (1) drive.

RAID 6:   This configuration is similair to a RAID 5 as the data is striped onto four (4) or more hard disk drives in small packets but there are two (2) revolving parity to storing fault tolerance for ECC. If any?single drive fails the system is still operational. The system can recover itself and rebuild the data from the failed or lost hard disk drive onto its new replacement and can be done as a “hot swap” if the system has that ability.  The benefit to the double parity is that during the lengthy RAID rebuild process, should a second drive fail, the RAID can still rebuild itself.   (0) Data storage configuration example:All drives should be either identical in regards to sector count and/or physical configuration of heads and tracks.  Mismatched capacity drives may work but would be limited to the smallest hard disk in that configuration and is always limited on the RAID software or hardware requirements.  Add the total capacity of all drives together minus two (2)  drives.

System administrators are constantly looking for ways to secure user data and maintain data transmissions during a system failure.  The initial implementation of the correct RAID configuration can save valuable time and money in the event of a systems’ hard disk subsystem failure.

Originally written by: J.D. Biersdorfer, writer for The New York Times

Technology Q & A

“A. Unless you are operating a power tool, loud clicking or grinding from a mechanical device - including a hard drive - may be a sign that something is about to break.

The complication with a hard drive, of course, is that valuable files are stored there, and there may be no easy way to rescue the data.

Hard drives are basically motorized platters spinning rapidly as a read-write head floats above on a cushion of air and magnetically inscribes the data onto the disk. All your files, folders and Green Day songs are stored on the disk’s magnetic surface.

There are other sources of computer noise, including loud internal cooling fans and even desk clutter that rattles with the natural vibrations of your computer. First, clear the area and listen closely to the machine.

Grinding noises can mean that the read-write head is scraping against the surface of the disk and damaging it. Clicking noises coming from a hard drive are also cause for concern, and may mean that the drive’s read-write heads are misaligned; the drive is probably damaged.

If you hear a high-pitched whine, your hard drive’s bearings may be on the way out, but you may be able to save most of the data if you get the machine to a computer-repair professional right away…”

“If your hard drive dies before you can back up the files, a data recovery service may be your last hope. … Disaster Recovery Group (www.disasterrecoverygroup.com)… specialize in extracting stranded files from broken hard drives…”