Data recovery technologies, data recovery tips, data recovery skills…
Ontrack Data Recovery Solution’ Contents:
1. Data Loss Dangers
2. Critical Data Risks
3. Challenges and Responsibilities
4. Protection, Detection, Correction
5. Finding the Optimum Solution
6. The Data Recovery Alternative
7. When is Data Recovery Necessary?
8. Data Recovery Case Studies
9. Final Analysis
10. Additional Information
URL: Ontrack Data Recovery Solution
Microsoft® SQL server is a business enterprise software package that manages data through a client/server relational database. There are four fundamental aspects to a SQL (Structured Query Language) server.
1. Database File
2. Relational Database Concept
3. Client/Server System
4. Database Management System (DBMS)
The Database File refers to the physical file that contains the data the SQL server manages. This file is more than just a container for data. SQL files, or .MDF files, are highly organized and complex. The file is designed like this so that SQL server can handle multiple data transactions at once.
The Relational Database Concept is the method employed to organize the data; this is separate from the internal organization of the file itself. Relational Database Concept systems use mathematical set theory to organize the data in the most effective way. Data organization is critical to maintaining the speed of the database server.
The Client/Server System refers to the part of SQL server that communicates with the operating system. This part of the system needs to manage the server’s resources, connections and managing multiple databases at the same time.
The Database Management System interacts and works will all the above items. Not only does this manage the internal structure of the .MDF file, DBMS also controls the Relational Database side of things and organizes the data. The DBMS of SQL server is the heart of the system.
Data loss situations-What can happen?
Data loss situations can occur at a number of different levels. The first level of data loss starts with the storage device. This can be a single hard disk or a SAN or RAID storage array. The second level of data loss can start at a file system level. The file system is a unique method of storing and organizing system and user files. The operating system controls the file system. If the information about where data files are on the volume are damaged or lost, then adjustments or repairs need to be completed at a file system level. Once the file system is repaired then the file’s data stream can be accessed correctly. Most operating systems have a utility that will automatically fix the file system. These utilities work to make the volume accessible. However, this can permanently damage the data stream of the file. The third level of data loss can occur within the file itself. As previously mentioned, .MDF files are quite complex. The internal structure can be corrupted to the point where the DBMS will not make the database available.
The solution to data disasters
The process of a SQL recovery begins with finding the database file requested. If the database file is inaccessible due to problems with the storage device, then should work to get that data extracted. If the file is missing, deleted or truncated due to problems with the file system, then should work to adjust or repair the file system to correctly point to the data stream of the file. And finally if the file system has no pointers at all to the file, then should search the entire drive looking for SQL data.
The next stage is to work on the database file itself. This is where the SQL toolset comes. These tools analyze the complex internal structures of the .MDF file and provide reports as to what tables are recoverable. The reports also list the number of data rows that will come back.
Once the evaluation is complete and authorization is given to recover the data, the SQL toolset will copy the data into another SQL server database. After this phase is complete, we can backup or archive the recovered data.
Remote Data Recovery is the fastest solution for SQL recoveries. The Remote Data Recovery process will copy the recovered data into a SQL server that is setup on you or your client’s site. They only need SQL server running. For best results I recommend that the storage device we are working on be connected to a SQL server, because all of the data transactions will be occurring on a single machine.
Overview of RAID
The heart of the RAID storage system is controller card. This card is usually a SCSI hard disk controller card (however, IDE RAID controller cards are becoming quite common). The task of the controller card is to:
1. Manage Individual Hard Disk Drives
2. Provide a Logical Array Configuration
3. Perform Redundant or Fault Tolerant Operations
RAID History
RAID is an acronym for Redundant Array of Inexpensive Disks. The concept was conceived at the University of California, Berkeley and IBM holds the intellectual patent on RAID level 5. The University of California, Berkeley researchers, David A. Patterson, Garth Gibson, and Randy H. Katz worked to produce working prototypes of five levels of RAID storage systems. The result of this research has formed the basis of today’s complex RAID storage systems.
Individual Drives Management
The RAID controller will translate and communicate directly with the hard disk drives. Some controller cards have additional utilities to work with the disk drives specifically, such as a surface scan function and a drive format utility. In the case of SCSI based cards, these controllers will provide additional options to manage the drives.
Logical Array Configuration
The configuration of the logical array stripes the data across all of the physical drives. This provides balanced data throughput to all of the drives—instead of making one drive do all the work of reading and writing data, now all of them are working together and the data is streaming across all of the physical drives.
The Operations to Redundant or Fault Tolerant
The redundancy in a common RAID 5 configuration is the result of using a Boolean mathematical function called Exclusive OR (XOR). This is commonly referred to as Parity. The XOR function is a logical binary process—its best to think of Parity as combination of the other drive’s data blocks. Every byte that gets written to one data block is calculated against the other data blocks and resultant Parity is written to the Parity block for that particular stripe. What makes this function so unique is that the math will always work regardless of what data block is missing. However, the limitation to RAID 5 is that only one data block can be missing—the math will not work if there are two blocks missing. In the working environment this means that only one drive can fail. The RAID 5 configuration will not provide proper redundancy if two or more drives fail.
As previously mentioned, the controller card is striping the data as well as performing the XOR function on that data as well—the amount of logical computations the controller is doing every second is staggering. Today’s RAID controllers are intricate pieces of hardware, including specially designed processors and SDRAM memory banks to provide performance and redundancy.
RAID Introduction
Storage systems preserve data that has been processed and data that is queued up to be processed and have become an integral part of the computer system. Storage systems have advanced just as other computer components over the years. The RAID storage system was introduced over 15 years ago and has provided an excellent mass storage solution for enterprise systems. Let’s get a little more history about the RAID concept and they work.
Common RAID Configurations —the pictures below graphically show how RAID Arrays are put together (this is handled by the RAID configuration.) Follow the letters to see how the data stripes jump between drives.
RAID Recovery
RAID storage systems are designed to deal with failure. While hardware failure is a strong reason why some RAIDs may fail, there can also be other failures that make the data inaccessible. If your client is having problems with their RAID Array, then Ontrack Data Recovery is your solution.
A RAID recovery evaluation is really the combination of two very important steps. First is the array rebuilding and this has the potential of taking the most time. This investment in time is required in determining the original configuration and getting a quality recovery. The second step is to work on the logical file system. Today’s enterprise journaling file systems are highly complex; if the RAID Array is out of order there will be thousands of errors within the file system and files will be corrupted.
Some of the design goals of the RAID storage system were to provide performance improvements, storage reliability and recovery, and scalability. The redundancy concept employed in the RAID system is unique and provides a method to recover if one drive should fail within the system. In fact, today’s RAID controller cards have the ability to continue reading and writing data even if one drive is ‘off-line.’
If you deleted an important file from recycle bin that you really needed, do you have any way to get it back? Some people hit the fan and begin to drastically panic if the file they deleted was very important. In fact, you can recover deleted files from the Recycle Bin. The file you deleted from the recycle bin hasn’t actually been permanently erased yet, it is still hidden deep within your computer’s hard drive. All you need to do is know how to find it, and with the aid of new advanced software’s, finding and recovering that deleted file can be as simple as a few clicks of your mouse.
A common misconception is that once you delete a file from the Recycling Bin it has been erased forever, and it is no longer present on the Hard Drive. Luckily for you this is not true, you see when you click empty recycle bin, windows does not actually delete the files, Those commands just generally delete a file’s name from the directory so it won’t show up when the files are listed. But the information itself can live on until it is overwritten by new files. Therefore the file has not actually been deleted; instead the space that it occupied has been freed up and listed as re-use space. Now until that file is overwritten by new data your file is still there and can be retrieved.
The first thing you should do if you want to get your files back is to stop downloading or installing any new data on the hard drive. The reason being, that once you install new programs or download new data onto the Drive it could use up the space created by your deleted file and it will be a lot harder to recover. Having more available space on your hard drive will increase your chances of recovery, as Windows avoids using up space that has recently been freed; therefore if you have plenty of room on your hard drive it will use that before it touches the space from the deleted file. Although I still strongly recommend you act as soon as possible and do not download any new material to your hard drive, that way you will most certainly have your deleted files back.
Therefore in order to recover deleted files from the recycle bin you must obtain a good Undelete Software, these software’s can recover data from almost any data drive like hard disks, USB drives, Zip drives, SD Cards etc.. The software’s can also recover data from data cards in digital cameras and cell phones. The good news is that most Undelete Programs offer a Free Download, so you can try out their software at no cost to see if you are able to recover your deleted files from recycle bin.
The IT industry has become even more complex in the past few years with the advent of regulatory compliance requirements that all publicly traded companies in the US and other regions must adopt.
Perhaps your organization is already working through these requirements. If you are a consultant or non-publicly traded company, you may not be bound by these regulations – however your clients may be, so this information is critical for anyone in the IT industry.
Regulatory standards affect the broad areas of data privacy, security, retention, protection and accountability. Within these areas, checks and balances act to preserve the information and data. Investigative processes verify the integrity of privacy; security and data protection and audits are required for accountability.
The legal and business requirements protect a company from investigations or consequences but they also help safeguard consumer and patient information. Here’s a list of some of the common regulatory compliance laws.
This is by no means a comprehensive or industry specific list but serves as an example of the amount of data regulations that are already in place:
Data Regulations
Sarbanes-Oxley Act
Known as SOX, this Act requires company financial executives to be culpable for financial reporting. Independent auditors review financial controls and processes to ensure accurate financial reporting. Controls of records and processes are preserved to prevent fraudulent activities.
Healthcare Insurance Portability and Accountability Act
The Healthcare Insurance Portability and Accountability Act requires, among other things, the securing of patient information.
European Union Data Protection Directive
The European Union Data Protection Directive (EUDPD) standardizes the protection of data privacy for citizens throughout the European Union (EU) by providing baseline requirements that all member states must achieve through national implementing legislation
Payment Card Industry Data Security Standard
The four major credit card associations in the United States (Visa, MasterCard, American Express, and Discover Network) adopted a consolidated data security standard (Payment Card Industry Data Security Standard; PCIDSS). Compliance is required of merchants accepting these cards.
Japan’s Personal Information Protection Act
The Personal Information Protection Act. The Personal Information Protection Act applies to government or private entities that collect, handle, or use personal information of 5,000 or more individuals
Gramm-Leach-Bliley Act
The Gramm-Leach-Bliley Act addresses the protection of nonpublic personal information, requiring that financial records are properly secured, safeguarded, and eventually disposed of in a manner that completely destroys the information.
Breach Notification Legislation
California’s Senate Bill 1386 (SB1386) requires notification to California residents regarding any breach to the security of a computing system containing personal information.
Regulatory compliance issues can be really summed up by these simple items: “Keep it, Secure it, and Preserve it.” This can mean extra equipment and IT policies to maintain control over informationthat users may have previously horded on their machines.
One of the most important aspects to regulatory compliance is the 100% accessibility to the stored data. During data storage disasters, companies that require speed and quality turn to Professional Data Recovery Company for getting access back to regulatory data. In other situations, software that facilitates retrieving data is part of some IT department’s compliance process.
One of the least reported risks to electronic information is storage system failures. What happens when the server you have for compliance fails? How do you cope with a quarter-end financial audit when the business system database becomes corrupt? Who do you turn to when your company is in the middle of an SEC investigation and the electronic message server goes offline? These types of situations happen to corporations everyday. To help minimize this risk, several risk mitigation policies that storage administrators can adopt are outlined below:
Offline Storage System — Avoid forcing an array or drive back on-line. There is usually a valid reason for a controller card to disable a drive or array, forcing an array back online may expose the volume to file system corruption.
Rebuilding a Failed Drive — when rebuilding a single failed drive, it is import to allow the controller card to finish the process. If a second drive should fail or go off-line during this process, stop and get professional data recovery services involved. During a rebuild, replacing a second failed drive may change the data on the other drives.
During an Outage – If the problem escalates up to the OEM technical support, always ask “Is the data integrity at risk?” or, “Will this damage my data in any way?” If the technician says that there may be a risk to the data, then stop and get professional data recovery services involved.
Doing the Recovery Yourself – Some IT departments may have staff that has worked with automated data recovery or hard disk storage utilities. Depending on the cause of the data loss these tools could actually limit recovery efforts because the drive is experiencing intermediate failures. Some utilities on the internet are ‘free’ and promise to fix dead hard drives. Verify the source of the software and make sure that it comes from a reputable company that has a standardized development and quality assurance (Q/A) process. Untested software can yield unpredictable results.
When user desktop or laptop computer storage systems fail, do not assume that that their files are backed up, or synchronized, on the file server. At the same time, never assume that the data is completely gone.
Today marks the 50th anniversary of hard drive storage. When IBM delivered its first hard drive on September 13th, 1956, few could have imagined the impact it would have on our everyday lives. The RAMAC (also known as ‘Random Access Method of Accounting and Control’) was the size of two refrigerators and weighed a ton. It required a separate air compressor to protect the heads, had pizza-sized platters and was able to store a then whopping 5 megabytes of data. Now you can do all that with a mere pocket drive! What’s more – the RAMAC was available to lease for $35,000 USD, the equivalent of $254,275 in today’s dollars.
25 years later, the first hard drive for personal computers was invented. Using the MFM encoding method, it held a 40MB capacity and 625 KBps data transfer rate. A later version of the ST506 interface switched to the RLL encoding method, allowing for increased storage capacity and processing speed.
IBM made technological history on August 12, 1981, with the launch of their first personal computer – the IBM 5150. At a cost of $1,565, the 5150 had just 16K of memory- just enough for a small amount of emails. It’s difficult to conceive that as recently as the late 1980s 100MB of hard disk space was considered ample. In today’s era, this would be totally insufficient, hardly enough to install the operating system, not to mention a large application such as Microsoft Office.
When asked about the limitations of the early PC, Tom Standage, the Economist magazine’s business editor says: “It’s hard to imagine what people used to do with computers in those days because by modern standards they really couldn’t do anything.”
As a result of these major breakthroughs, the industry has grown from several thousand disk drives per year in the 1950s to over 260 million drives per year in 2003. During this period, the cost of magnetic disk storage has decreased from $2,057 per megabyte in the 1960s to $.005 today.
The future is bright
At present, the standard 3.5 inch desktop drive can store up to 750 gigabytes (GB) in data. But disk drives are set to become even smaller, more powerful and less costly. According to Bill Healy, an executive at Hitachi, drives containing hundreds of gigabytes will be small enough to wear as jewelry. “You’ll have with you every album and tune you’ve ever bought, every picture you’ve ever taken, every tax record.”
Having five disk drives in your household is becoming increasingly commonplace: PCs, laptops, game systems, TiVo® video recorders, iPod® – just to mention a few. Experts believe that someday households will have up to 15 disk drives, some of which may appear in your TV set, cell phone or car.
In fact, the industry is expected to deliver as many drives in the next five years as it did in the last 50 years. Industry analysts such as Gartner, IDC and TrendFOCUS believe that the global hard drive market will continue to experience impressive unit and revenue growth.
Take the good with the bad
As new devices hit the market, and the amount of stored data escalates the potential for data loss is greater than ever. No matter how strict your back-up policy or how heavily you invest in data protection – somewhere along the line data loss will occur.
Your hard drive just stopped working. It never made any odd sounds like screeching, popping, or clicking, and it didn’t crash. It just quit and it has some priceless data that isn’t backed up to another device. This guide may help you troubleshoot and correct any problems related to your drive. Note: this is much more likely to work on a newer drive than an older one, especially when searching for a sacrificial clone. Be sure to read all warnings before proceeding.
Steps:
1. Remove the hard drive from the computer or device.
2. Examine it carefully for ‘hot spots’ or other damage on the external controller board.
3. Move it gently from side to side and then front to back. Listen for metallic rattling noises. Don’t be too rough when you shake the drive. The drive’s heads are probably loose if there is a rattling sound. If so, stop here and contact your computer or drive’s manufacturer for a replacement. Data recovery is extremely expensive. If you need your data regardless of the cost, contact a data-recovery specialist.
4. Place the drive back into the computer or device.
5. Switch drive pin settings. This only applied to PATA (IDE/EIDE) drives. In a computer, if it was slave or ‘cable select’, try making it ‘master’ and plugging it in alone, or plugging it into an external drive adapter or external drive case (i.e. USB).
6. Try it on another IDE, SATA, or SCSI connection, depending upon the drive’s type.
7. Try other IDs and another controller if it is a SCSI drive.
8. Connect the drive with another data cable.
9. Attempt to access the drive on another device. If possible, connect the drive to another computer with a working drive and attempt to access it through that computer’s operating system.
10. Another option to try is to freeze the drive for several hours, let it warm to room temperature, and try the drive again. If successful, backup all data immediately and consider replacing the drive because it will probably fail again soon.
Replace Controller Board
1. Inspect the drive’s controller board carefully to see if it can be removed without exposing the drive’s platters. Most drives will have an externally-mounted controller board. If not, stop here.
2. Find a sacrificial drive. It is important to match the exact same model number and stepping.
3. Remove the controller board of the failing drive. Learn everything about how it is connected to the drive. Most drives are connected via ribbon cables and pin rows. Be gentle. Do not crimp or damage the connectors.
4. Remove the controller board from the working drive. Again, be extremely careful.
5. Attach the working board to the failing drive.
6. Connect the drive to your computer or device and test. If it works, immediately copy your data onto another form of media or a different hard disk drive. If that didn’t work, try to re-assemble the sacrificial drive with the working controller board. It should still work. Re-assemble the failing drive. If that works, it wasn’t the externally accessible board.
Tips
1. Back up your data!
2. If data comes in faster than backups, and is precious like this, consider RAID 1, RAID 5 or RAID 10 disk configurations. A RAID array will keep running when one physical drive dies. A good one will even re-write a replacement drive that’s “hot swapped” into it without stopping.
3. NEVER use RAID 0 for anything but scratch data. It’s fast, but has no redundancy, so it’s much more likely to crash than a single drive, and take your data with it in a really irrecoverable manner. Especially ‘built in’ PC motherboard RAID configurations. Virtually all motherboard RAID controllers are bad.
4. Programs like GRC’s Spin rite does an excellent job at getting down to every last bit and ensuring that everything is working on the most basic of levels, however, if it finds that a sector of a hard drive is corrupted, it will attempt a recovery of it. It has saved many hard drives from failing, and has helped recover gigabytes of data. Spin rite is in its 6th version and has proven very successful. Please note, while Spin rite and other software hard disk recovery programs work well, they will not permanently fix a problem every time. Therefore, it is recommended that software recovery only be used to backup the data.
5. Some programs, such as Spin rite mentioned above, perform maintenance on hard drives to prevent flaws from forming.
6. Putting the hard drive in the freezer has been known to revive a failing hard drive for a short time, possibly long enough to recover files.
Warnings
1. Configuring drives in a RAID 1, 5, or 10 is not a substitute for a regular backup routine. RAID controllers will fail eventually, writing bad data to the drives. RAID controller failure is difficult to detect until it’s to late.
2. If you are not good with delicate hardware tinkering, don’t follow these instructions. Find a professional or someone who is experienced with hardware tinkering to try it for you. Don’t hold it against the person if they fail to recover your data. Most retail outlet technicians are not trained for component-level repair of this type.
3. Static electricity grounding precautions should be observed.
4. You will void both hard drive warranties. These instructions are for recovering data that is far more valuable than the drives themselves.
5. If the failing drive was sold with a computer or device, you may void the manufacturer’s warranty if you follow these instructions. Make sure the data, or your attempt to recover data, is worth voiding that warranty.
6. Do not disassemble a hard drive in a manner that will expose its disks/heads unless you plan to just throw it away afterwards. That operation must be done in a ‘very clean’ clean room. If you don’t have a completely dust-free environment and gear, opening the hard drive and exposing the platters and heads poses a great risk in ruining the drive.
7. Don’t believe you’ve “never had a problem” with RAID 0 array, or even “never had a problem” from not backing up your data. Just because the drive in question was working for a certain period of time before it failed does not mean it was configured properly.
8. After the a controller board swap, you will certainly have two failing hard drives, whether you recovered the data or not. Do not re-use these drives. Consider other identical drives you purchased from the same batch ‘suspect’.
9. This procedure is not for logically erased data (i.e. ‘un-formatting’). This procedure is for physically inoperable drives with intact data.
A common misconception about hard drive data recovery is that repairing hard drives means replacing parts. If only it were that easy! Hard drive technology is always changing— manufacturers are constantly using different mechanical designs.
The mechanical precision of today’s hard drives makes head assembly replacement nearly impossible without specialized tools. Platter removal is dangerous and will affect how the drive reads the sectors. As previously mentioned if just one component is out of alignment, the drive will not find the required sectors. If the hard disk electronics cannot find the sectors requested by the controller, it may endlessly try to find those sectors or it will shut down the unit.
Mechanical precision is just one side of hard drive technology – the electronics are just as finite. Exchanging circuit boards between drives used to be a quick way to work around a failed circuit board in the past. The electronics are much more complicated, and as a result the different revisions of a circuit board are rarely compatible. The innovations of the past 15 years have made a circuit board swap as a solution a thing of the past.
Today’s hard drives have no room for errors when it comes to platter and head alignment. The tolerances are so exacting that hard drive manufacturers even design ways to keep the Base-Casting Assembly, where all the components are attached to, from shifting due to high temperature situations. For instance, one hard drive manufacturer of high performance SCSI based drives actually designs their Base-Casting Assembly with pre-stress points. The assembly does not line up from corner to diagonal corner—it’s pre-torqued. When the casting assembly heats up, the unit actually twists back (thermal expansion) into a true line-up from corner to corner. With the byte-density of most large hard drives today being 4gb to 6gb per square inch, absolute precision is required for these high capacity and high speed drives to operate reliably. Hard disk manufacturers are working to increase how many bytes can be squeezed into a square inch.
Today’s hard drives are designed from basic primary components as the foundation first and then other components are built around that. For instance, research and development improvements in platter and magnetic media require research and development improvements in head design. These designs require that the electronics be ‘custom-made’ for that drive. Hard drives are ‘fine-tuned’ to the properties of the storage media and read/write heads. Similar to how a radio is tuned to a specific radio frequency; hard drives are finely tuned to complement data signals that are read from the storage media.
Hard drive manufacturers make large batches of drives so there will be similarities between drive models. However, the Revision Code (proprietary hard drive read-only software that is used by the electronics to manage and operate the hard drive) changes frequently within the same model and batch. Hard drive innovation requires drives to be constantly improved upon. All of this requires extensive training in electronics and computer science to be able to work with these storage devices.
The three most common problems seen today are: 1. The drive makes a repetitive clicking sound when power is applied (this may not always be audible to you). 2. The drive is completely dead, not spinning at all. 3. The computer bios sees the drive, but there is no boot and a boot from a floppy will not gain access or you get an error message that says ‘Invalid media type reading drive X’. Of course there are other issues such as flooding (never turn a wet drive on!), fire and other natural and unnatural disasters all of which require a top-notch data recovery company to work with.
If your drive is making a clicking sound, 9 times out of ten this means that the heads are bad and cannot read the information needed to get the drive to a ‘ready’ state. This can be due to two factors: physical head crash whereas the heads scrape some of the media off the surface of the platters thus destroying the heads in the process or the heads just go bad. The result is the same, the drive clicks. In this type of situation, you can expect an expensive data recovery because of what is needed to extract the data. The drive will have to be opened in a clean room environment, the heads will need to be replaced which requires an identical drive be purchased just for parts, and a skilled engineer will have to perform the difficult and meticulous task of aligning these new heads so they read the data properly. If indeed the media has been scored, there are many cases where there is nothing that can be done about it because so much of the recording material has been scraped off. Keep in mind that drives now sold are spinning at an incredible 7200 to 10,000 rpm, and that with this kind of speed disaster can be swift when it happens.
There seems to be a large number of electrical issues with drives these days, weather it be natural as in lightning strikes or man-made as in power outages and poorly manufactured power supplies. There are also known issues in many models of Maxtor, Western Digital and Quantum drives where a certain chip will simply burn up and cause the drive to stop spinning. About two years ago or more, Western Digital had a 500,000 drive recall as the result of a defective chip used in making many different models of drives. Over the last year or more, Quantum drives of many models had a similar issue, except this time, the numbers of affected drives was much higher. This was the driving force behind the acquisition of Quantum’s hard drive lines by Maxtor! Maxtor is still reeling from the huge numbers of returned drives on a daily basis. One of the big problems is that manufacturers do not put a fuse on the drives’ electronics anymore. You might say, “This would be an easy fix, I’ll just get another drive of the same model and swap the boards myself”. In an ideal world this would be the case but another factor most people do not know is that for each model drive made by a manufacturer, there can be over a dozen different revisions of the electronics even though the model is identical! This fact can make a simple problem very complex. Don’t look to the manufacturers for help with this either, they will not.
If the drive is seen by the BIOS of the computer, and you cannot access it by booting from a floppy in the case of a WIn9X or ME drive this means that for some reason the areas that define the partitions of the drive or the boot parameters have been corrupted. This can be caused by a virus, a computer or software bug, using a third party partitioning software, running Fdisk or a number of other reasons. This type of situation can be an easy fix for a professional or it can be a more difficult one depending on the extent of any additional damage to the file system or data structures. Usually, this type of problem is an easier one to deal with, because the drive at least still works. In the case of an operating system other than Win9X like NT, corruption the NT data structure can be a very complex mathematical problem and can be an expensive recovery as well due to the time it takes to solve. Operating systems like Unix and Novell as well as Spanned sets or Raid drives can definitely be an expensive recovery due to the complexity of these configurations.
It is important that you never run utilities such as scandisk, Norton disk doctor or any other such utility on a drive you suspect has a hardware failure. This can make recovery of your data difficult or even not impossible in some cases. These software tools work best on simpler types of problems and have no way of dealing with hardware issues. If your data is important, and you have doubts on what to do, call a professional. Also beware of technicians running these tools without your knowledge, as the results can be just as deadly.
When a data recovery company receives your drive, if it is possible and the drive is operational, a copy of your data is made sector by sector onto another drive (make image of your DATA) so that your data is not harmed in any way. This prevents mistakes, and allows the engineer to run utilities and make changes to a copy of your drive only and not the original.
Hard drives these days are worse than ever. You may find this a surprising statement, but it is true. Due to slimmer margins, and high competition, manufacturers are making drives as inexpensively as possible and more failures are the result. As of this moment, Fujitsu has top marks for reliability in desktop hard drives followed by IBM. In notebook drives, IBM and Toshiba have top billing. An important point to note is that Hitachi makes the absolute worst notebook drives in the industry with the highest catastrophic failure rate followed by Fujitsu. Dell has just decided to go exclusively with Hitachi now in their new notebooks, so beware!
Here is my old standby: Make believe that tomorrow when you turn your computer on that it is not going to work, and what is it that you want today that you will have to do without tomorrow! Back it up!
