mhdd hard drive test. How to use the MHDD program correctly? How it works
The most accurate way is to check them through DOS using the MHDD program. In this case, the HDD will not be loaded with third-party programs and processes, only one program will access it, this will reduce the response time and provide reliable results.
What can not be said about, which, working from under Windows, may not produce quite correct results. This is due to the fact that at the time the utility is running, third-party services and processes are running that access the hard drive, increasing the response time.
This means that if you run the test and continue to use the computer at that moment, you will see a large number of slow or inaccessible sectors in the test results. And we don't need it at all.
What is this program
MHDD is a professional free solution for checking hard drives for errors and defects. It boasts a very wide functionality that allows you to carry out not only basic and advanced scans, but also perform HDD recovery.
Since the installation does not take place on a computer, but on a USB drive, MHDD is suitable for all operating systems, including Windows 7 and 10 (32 and 64 bit). It is distributed absolutely free of charge, the interface is quite simple, albeit completely in English.
And now, I propose to move on to detailed instructions for its use.
Where can I download
First you need to download the latest version of MHDD from the official site developers, be sure to in .ISO format, saving it to your computer. By default, the “.zip” archive is downloaded, do not forget to unzip it.
ISO is a special format for writing to a USB flash drive or disk, designed for subsequent launch through DOS.
The utility is also included by default in popular free Live CDs: Hiren's Boot CD, Ultimate Boot CD, 2k10 Live CD and others.
Create a bootable USB flash drive with MHDD
To write to a USB flash drive, we will use a special free program "UltraISO". It is free and distributed in Russian. So please download and install it first.
Save the settings and restart the computer again.
Instructions for use
Now let's talk about how to use the MHDD program correctly.
Next, all hard drives connected to the computer will be displayed. Each HDD will have a serial number to the left of its name. Enter the required number and press "Enter". In my case, this is the number "2". To redefine the disk with which you plan to start working, you need to press the combination "SHIFT + F3".
Now you can start working with the hard drive. By default, the MHDD program will offer you to familiarize yourself with all the commands that are available to us. To open the list of commands, press the "F1" key.
Let's analyze the most popular of them:
As an example, I will run a normal surface scan for bad blocks. To do this, I enter the command "SCAN" and press "Enter".
In the window that opens, I leave all the default values \u200b\u200band press "F4" to start the scan. In this case, all information will be saved, eventually I will receive a report on existing problems.
Just want to draw your attention to the fact that there are other functions:
- Start LBA– the starting point from which the scan will start.
- End LBA- final destination.
- Remap– is used in cases where it is necessary to perform a scan with automatic remapping of bad sectors (used to restore the health of the hard drive). Takes the value " OFF" and " ON”, that is, turn on - turn off.
- timeout– sector read delay time. After the expiration, the transition to the next area will be made.
- Spindown after scan– stops the HDD after the scan procedure is completed.
- Loop test/repair– cyclic check.
- Erase Delays- used to completely overwrite slow or inaccessible sectors. In this case, some of the information on the drive will be deleted. Accepts the value "OFF" and "ON".
To change the parameters in the MHDD program, use the "Enter" key, to move to another parameter, you can use the arrows on the keyboard.
Analysis of scan results
After the check is completed, you will see a window with detailed information in the form of multi-colored squares and letters.
What does each of them mean:
- Gray squares (3-50 ms) - show the total number of the fastest sectors with which no problems are observed.
- Greens (<150 ms) - talk about the presence of slow sectors. A large number of them (above 500) can slow down the speed of the hard drive. However, the presence of green squares is inherent in each drive and is the norm (in reasonable values).
- Orange (<500 ms) - very slow sectors, significantly reducing the speed of the drive. Ideally, they should not exist at all. The presence of at least one indicates the beginning of problems in the operation of the hard drive.
- Red (>500ms)- bad sectors (bad blocks). Significantly slow down the work of the hard drive, cause various failures in the operation of Windows and programs.
- UNC– a failed area that cannot be recovered. Most likely this is a "logical bad block". Usually eliminated by overwriting with the "ERASE" function.
- AMNF– missing address label. Most often occurs due to a malfunction of the hard drive hardware. You can try ERASE or REMAP, but in most cases this does not work.
- ABTR- read request denied. It may appear as a result of a hardware malfunction, or due to the incompatibility of the MHDD program with a specific hard drive.
- IDNF– Identification number not found. Speaks of a malfunction, or an unsuccessful attempt to access the area.
- T0NF– zero track was not found, recalibration failed. Speaks of a defective HDD.
Recovery procedure
Now, judging by the report received, we can proceed further according to the instructions.
It must be remembered that the "Erase Delays" command will only delete some of your files, while the "ERASE" command will completely delete all files. Therefore, I first recommend saving all important files to another medium.
Then we re-check. If some bad blocks remain, then it is obvious that they are caused by a physical malfunction of the hard drive. In this case, only the "REMAP" option, or replacing the drive, will help. Otherwise, such HDD may fail at any time.
Now about how I do it. To begin with, I start a normal scan with the Remap function. Then I start Windows and save all the information to another medium. Then, using the MHDD utility, I overwrite the damaged areas with the “ERASE” function. This approach increases the chances of effective HDD recovery and saves time.
SMART Analysis
In theory, this is the topic of a separate article, but I would like to touch on some values that somehow affect the result of the check and generally show the current state of the hard drive.
To open SMART in the MHDD program, you can use the F8 key or the "SMART ATT" command. We pay attention to the column "RAW". 
The most significant attributes:
- Reallocated sectors count– total number of automatically reassigned sectors (bads).
- Current pending sectors– sectors that are in the queue for reassignment.
- Ultra ATA CRC– the number of errors that occurred during data transfer via SATA cable. The value should be set to zero. Eliminated by replacing the cable or SATA connector.
What actions to take in a particular case, read in the previous section.
Issues you may encounter
It happens that the MHDD utility, even though it is displayed in Windows. It's most likely a physical problem. Try connecting the device to a different connector using a new SATA cable or remove oxides on the board.
If the device emits, then most likely the matter is in the internal mechanism, then only a replacement will help.
A hang-up at the verification stage can also speak of a faulty mechanism. Or the HDD dump in the main menu with the message "driver has been disconnected".
Detailed video on working with MCDD
youtube.be/8gYB4u_2rzc
Updated: 2018-10-19
Professional help
If you are unable to fix the problem yourself,
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I bought a new hard drive (HDD) or there is a suspicion that your old HDD is no longer the same - I strongly recommend checking it for bads.
Bad, bads, bad sector, bad block- (from English “ bad” – bad) – bad, unreadable, unreliable, unreliable file, disk sector.
- Mhdd official website (in Russian)
- Download the latest iso image (version 4.6 at the time of writing) mhdd32ver4.6iso
I will give step-by-step instructions for testing HDD using an example program MHDD. The program, with proper skill and experience, gives a chance to correct some bads, out of ignorance it is better not to try to fix anything !!!. But checking the health of the disk is quite simple and painless, and I’ll write about it.
How does scanning work?
- MHDD sends a command VERIFY SECTORS with number LBA(sector number) and sector number as parameters
- The hoarder raises the flag BUSY (disk locked)
- MHDD start timer (the timer measures the disk lock time, i.e. when it was BUSY or in Russian - busy!)
- After the drive has executed the command, it lowers the flag BUSY
- MHDD calculates the time spent by the drive and displays the corresponding block on the screen ( tabular part on the right ). If an error occurs ( bad block), the program outputs the corresponding letter that describes the error.
MHDD repeats steps 1-5 until the end sector.
How to understand the scan results?
The presence of red >500ms) blocks on a completely healthy drive is not allowed. I sound the alarm when green blocks appear (< 150ms ). You can try to fix these blocks by erasing the entire surface of the disk (naturally, all data will be lost) and, if this does not help, you can do findings(the drive is no longer reliable enough).
Letter-character blocks indicate the presence of BAD blocks on the surface.
Decryption of mhdd errors:
- UNC(Uncorrectable Data Error) - Failed to correct the data with redundant code, the block was declared unreadable. It can be either a result of a violation of the data checksum or a result of physical damage to the HDD;
- ABRT(Aborted Command) - hdd rejected the command as a result of a malfunction, or the command is not supported by this HDD (possibly a password is set, an outdated or too new model ...).
- IDNF(ID Not Found) – Sector not identified. Usually talks about the destruction of the microcode or the format of the lower level of the HDD. For serviceable hard drives, this error occurs when trying to access a non-existent address (the problem is that modern sector screws do not always have headers);
- AMNF(Address Mark Not Found) - it is impossible to read the sector, usually as a result of a serious hardware problem (for example, on HDD Toshiba, Maxtor - indicates a malfunction of the magnetic heads);
- T0NF(Track 0 Not Found) - it is impossible to recalibrate to the starting cylinder of the working area. On modern HDDs, it indicates a malfunction of the microcode or magnetic heads;
- BBK(Bad Block Detected) - A bad block has been found. Error is deprecated;
You can learn more about these errors in the description of the ATA standard at www.t13.org (but finding the right document there is a tedious task).
Disk boot failure, insert system disk and press enter. An inscription that sends legions of goosebumps down your spine, each one the size of a hard drive. According to the law of meanness, this happens when nothing portends trouble. But do not rush to frantically restart the system - this is a game of Russian roulette. It is better to boot from another medium and take up a thorough check. A proven tool - MHDD - will help in this.
Introduction
If SMART shows problems, most often this means one thing: the disk is about to start to crumble, and even unnecessary OS loading can affect. The next thing to understand is the software "bads" or hardware ones on it. If there are not so many hardware ones, then you can still try to bring the disk back to life.
I think you have heard of products like MHDD and Victoria. They are indispensable for low-level hard disk work and will help you accomplish great feats of recovery and diagnostics. About Victoria, now it's time to deal with the second - archaic, but still mega-useful utility.
MHDD is a small but powerful freeware program that is designed to work with drives at the lowest level (as far as possible). The first version was released by Dmitry Postrigan in 2000. It could scan the surface of an IDE drive in CHS mode. Now MHDD is much more than diagnostics. With MHDD, you can do anything: diagnose drives, read and write arbitrary sectors, manage the SMART system, password system, noise management system, and change the size of the drive.
Despite the fact that working with MHDD is also possible through installed Windows, I highly recommend burning the image to a USB flash drive or an external (or second boot) drive and booting bare DOS from there. Believe me, in a hardware issue it is better to exclude as much as possible all the links in the chain that can lead to glitches or computer freezes during operation.
Oh those interfaces
Not every interface can be correctly recognized by the program.
SATA interface. There is a possibility that the disk will not be detected in MHDD. The reason may be the operating mode of the SATA controller (IDE and AHCI) in the BIOS. MHDD, alas, does not support AHCI mode. BIOS settings need to be changed. Worst of all, not all motherboards now support this mode. The only way out can be to use a machine with a suitable motherboard or to refuse MHDD.
IDE interface. This interface is characterized by the distribution of devices on the loop - master / slave. By default, MHDD hides all devices in slave mode. There are two ways to fix this. The first is to change the location of the hard drive (switch the jumper to master) and check that the settings in the BIOS match. The second way is to try changing the disk number to 2 or 4 in MHDD. And don't forget about the mhdd.cfg configuration file, which is in the CFG folder. In this case, the PRIMARY_ENABLED=TRUE parameter is important.
SCSI interface. The SCSI controller driver may not be detected.
USB interface. It is theoretically possible to connect a disk via USB using an additional driver and program settings. The driver emulates the mode of operation via SCSI. It is also necessary to disable all unnecessary USB drives. The target disk must be connected before MHDD can be loaded. You will need to write in config.sys: device=X:\USBASPI.SYS /w /v , where X:\ is the path to the disk.
So, I take one of the broken disks from the shelf (I usually stick a broken label on them) and now I will try to resurrect it to show you how it works in practice. I had a WDC screw WD7500BPVX-60JC3T0 on my hands with a vinaigrette instead of the system and all the files on it.
Since the situation is so sad, I can format the disk up and down with a clear conscience, which greatly simplifies my task. But first, let's deal with a little theory and recovery plan.
getting ready
Initially, the disk must be initialized by the program, which is quite logical. After that, a surface scan is performed, which gives an understanding of the current state of affairs: MHDD will show the state of the hard surface. Then you will need to format the disk and check again. Usually at this stage, the soft-bads disappear, and only the hard ones remain. Then it will be possible to execute the REMAP procedure in order to reassign the bad blocks to the service area.
The main problem is that the service area is not rubber, and even after all the operations you need to look after the disk. If bad blocks continue to appear, then the disk, no matter how hard you try, is no longer a tenant. But in more successful cases, this method should help. As practice shows, after a remap, a disk can work for a very long time and even outlive its neighbors in the basket. Other times, it dies immediately after the reboot - it's just as lucky, and it's almost impossible to predict the effect.
Don't kill
Ditching a disk is much easier than restoring it. For example, everyone knows (or should know) that disconnecting the cable during operation leads to sad consequences. We also strongly discourage you from thoughtlessly switching flags and executing commands in MHDD. Read the documentation carefully and don't start doing something if you don't fully understand what it can lead to.
Well, you can get down to business! First, create a bootable flash drive. For this I recommend - full instructions and DOS itself is. When the media is ready, all that remains is to throw MHDD into its root, so as not to once again climb directories from the command line.
In order for the disk connected to the first channel to be accurately displayed, you need to edit the mhdd.cfg config, which is located in the CFG folder.
PRIMARY_ENABLED=TRUE 
As I said, scanning of any device is possible only if it is determined by the ID or EID commands (or by pressing F2).
Scanning
To scan, type SCAN and press ENTER or use F4. A menu will appear from which you can change some of the settings. By default, the start sector is zero (start sector). The end sector is equal to the maximum possible (the end of the disk). All functions destructive to user data (Remap, Erase Delays) are disabled by default.
Let's go through the scan options.
- Start LBA- the initial sector for scanning, by default 0, that is, the beginning of the disk.
- End LBA- sector of the end of the scan, by default the end of the disk. Sometimes it is more convenient to scan not the entire surface (especially when the disk volume exceeds several terabytes), but only the work area where the OS is located. For example, disk C is 50 GB, then the target area will be 2 * 50 * 1024 * 1024 = 104 857 600th sector. You can calculate it easier: (volume * 2) * 1,000,000, total 100,000,000.
- Remap marks the sector as bad in a special service area, after which the disk does not access it.
- timeout- delay time for reading a sector, after which the check proceeds to the next sector.
- Spindown after scan- stop the hard disk after scanning.
- Loop test/repair- to carry out scanning or checking cyclically.
- Erase Delays- erase sectors in which read delays are detected.
Press F4 again to start the scan. MHDD scans drives in blocks. For IDE/SATA drives, one block is equal to 255 sectors (130,560 bytes).
Here's how scanning works:
- MHDD sends a VERIFY SECTORS command with LBA number (sector number) and sector number as parameters.
- The drive raises the BUSY flag.
- MHDD starts a timer.
- After the drive has executed the command, it omits the BUSY flag.
- MHDD calculates the time spent by the drive and displays the corresponding block on the screen. If an error (bad block) is encountered, the program outputs a letter that describes the error.
MHDD repeats steps 1-5 until the end sector. If a scan log is needed, it can always be found in the log/mhdd.log file. During the scan, you can see many rectangles of different colors. So that you are not too scared, I give an excerpt from the help:
The presence of red (>500 ms) blocks on a completely healthy drive is unacceptable. If they are, it is necessary to erase (erase) the entire surface of the disk and, if this does not help, get rid of delays, we can conclude that this drive is no longer reliable enough. Alphabetic blocks like x , S , etc. are not allowed: they indicate the presence of bad blocks on the surface.
The first thing to be done is to completely clear the surface with the erase command. If this does not help, then scan with the EraseWaits option enabled. If the bad blocks have not disappeared, you should run scan with the Remap option enabled.
Restoring
If the scan reveals errors, the first thing to do is to copy all the data from the drive (if you need them, of course). In my case it was irrelevant. Then you need to completely clear the surface using the ERASE command, which erases each sector on the drive.
The drive will recalculate the ECC fields for each sector. This helps to get rid of the so-called soft-bad-blocks. If erasing does not help, run a scan with the REMAP option enabled.
If you see that each block contains an error, do not try to erase the drive or scan with the REMAP option enabled. Most likely, the drive's service area is damaged, and this cannot be fixed with standard MHDD commands.
The attentive reader, looking at the pictures of the disk scan, probably whistled and shook his head in dismay. Yes, my disk, while I was writing the article, died completely. The number of hardware bads exceeded all allowable limits, and by the time the last lines of the article were stuffed, it was already crunching like a Belarus tractor. This is by the way that if the disk starts to crumble, then you cannot trust it, especially if hardware bads appear. Remap can help when the disk has not yet begun to actively crumble, but defects have appeared on the surface. In any case, even if you managed to fix it, use such a disk only for non-critical data and in no case as the main one.
What do the indicators indicate?
- BUSY- the drive is busy and does not respond to commands;
- WRFT- write error;
- DREQ- the drive wants to exchange data with the outside world;
- ERR- an error occurred as a result of some operation.
When ERR lights up, look at the top right of the screen: the type of the last error will be displayed there:
- AMNF- Address Mark Not Found - access to a specific sector failed. Most likely means that the sector is corrupted. However, immediately after turning on the drive, just the opposite is true - it indicates the absence of problems and reports the successful completion of internal diagnostics;
- T0NF- Track 0 Not Found - zero track not found;
- ABRT- Abort, the command is rejected;
- IDNF- Sector ID Not found;
- UNCR- Uncorrectable Error, an error not corrected by the ECC code. Most likely, in this place there is a logical bad block.
Two more indicators may appear at the top: PWD signals the set hardware password, HPA appears if the drive size has been changed using the HPA command (usually used to hide bad blocks at the end of the disk).
The Victoria program is designed to test various drives: HDD, flash, RAID arrays, and also allows you to hide HDD surface defects, if such a possibility is available. The author of the program is Sergey Kazansky, distributed free of charge, you can download http://hdd-911.com/
Brief description of the program
On Vista and older systems, the program must be run as Administrator even if your account has administrator rights.
The program window is divided into several tabs: Standard, SMART, Test, Advanced and Setup. The API and PIO switches change the mode of operation of the program with the disk being tested. PIO mode requires support from the motherboard chipset. Modern systems younger than about 2011 do not support this mode of operation of the program, so we will not describe it. Let's give a brief description of the control elements in the tabs.
Standard. The window on the right shows a list of drives installed in the system. These are not only hard drives, but also USB flash drives, SD, CF and other memory card readers. They can be tested too. The device for testing is selected by clicking on the desired item. Immediately to the left in the Drive ATA passport window, information about the selected device is displayed. Seek, Acoustic menegment & BAD "er runs the seek test, allows you to manage AAM (if supported by the disk) and simulate bad sectors on the disk.
S.M.A.R.T. When you press the Get SMART button, SMART is read. USB drives are not supported. The rest of the SMART ON, SMART OFF, Auto save attributes ON/OFF buttons enable/disable SMART monitoring and save read attributes.
test. The main tab with which we will work in the future. The Start LBA/End LBA windows define the beginning and end of the region under test. By default, the entire disk is tested. Pause - pauses the test, the value changes to Continue. Start - start the selected test, change the value to Stop - stop the test. Rhombus with green arrows - moving forward or backward on the surface of the disk. Block size - the size of the block of sectors read at a time, you can leave it alone. Timeout - the time after which, in the absence of a response from the drive, the program will transfer to the next sector. End of test - what to do at the end of the test: stop the disk, start the test again, turn off the disk or turn off the computer. The color bar shows the number of blocks with the specified read time. Verify, Read, Write switches - test selection. Verify - check: the disk reads the sector, but does not transfer its contents to the computer. Read - Reads a sector into the computer. Write - erases a sector - this test destroys user data. Switches Ignor, Remap, Restore, Erase - the mode of working with bad blocks. Ignore - skip. Remap - attempt to remap a sector from a reserve. Restore - try to read data and write back (does not work on modern disks > 80GB). Erase - an attempt to write to a bad sector. It can fix it if an incorrect checksum (CRC) is written to the sector. > - execution of the test ahead.<- выполнение теста назад: с конца диска. >?< - чтение по случайным адресам. >|< - тест «бабочка»: чтение попеременно сначала и с конца диска. Break All – отмена всех команд. Sleep – остановить диск. Recall – включить диск снова (после sleep).
advanced. The main window shows the contents of the sector specified in the Sec field. The window below shows the contents of the partition table by clicking the View part data button. The MBR ON/OFF buttons enable/disable the ability to recognize partitions in the operating system.
An example of working with the Victoria program For an example of testing a disk, let's take a faulty HDD WD2600BEVT, which has surface damage and bad attributes in SMART. We launch the program, select our disk and see the following: on the left we see the parameters of the selected disk.
Next, on the SMART tab, you can see the SMART of our disk. There he is.
We see that the program interprets it as bad. Let's consider in more detail.
Attribute 5 Reallocated sector count - the number of reassigned sectors 1287 - the disk is "stripping".
Attribute 197 Current pending sectors - the number of candidate sectors for reassignment, if the 5th attribute is overflowing, it indicates that the disk is "crumbled", the surface quickly degrades.
This means that if data is needed from a disk, then you need to copy it immediately, and not try to repair such a disk. The actions that we will consider next can lead to loss of information.
UNCR errors are visible - these are bad, unreadable sectors - bads (bad blocks).
You can uncheck the Grid checkbox, then the disk reading schedule will be displayed. In places of bads, speed dips are visible, marked in red.
At the end of the test, you can try to hide bad sectors by selecting the Remap mode. This can help if there are bads, but SMART is not BAD yet. It looks like this:
The result of the remap can be viewed by reading the smart disk. There he is:
The value of the 5th attribute increased and became 1291. During normal operation, disks, in the absence of access to them, run their own procedures for checking and reassigning sectors in the background, and the number of candidates for remap, in the hundreds, indicates that the disk can no longer maintain a conditioned condition and needs to be replaced. And the SMART status does not always adequately describe the state of the disk - it can be badly damaged, and the SMART status is displayed as GOOD.
The book outlines methods for recovering data from various storage media - hard drives, RAID arrays, CDs, DVDs, flash memory cards, camera cards and mobile phones. The repair of damaged equipment is considered in the publication only as one aspect of the entire data extraction process. The main topic is the extraction of data damaged due to physical or logical violations in the operation of a computer system or incorrect user actions. The book discusses the recovery of accidentally deleted files, the extraction of valuable information from broken hard drives; describes programs and methods for recovering data from damaged RAID arrays, which is critical for the operation of corporate computer systems.
The book does not require special preparation of the reader: simple step-by-step data recovery procedures are preceded by a description of the principles of their storage on various media.
Book:
MHDD is a small but powerful free program designed to work with hard drives at the lowest level (bypassing the BIOS). It can diagnose drives, read and write arbitrary sectors, manage the SMART system, and much more.
The distribution kit of the program can be found on the developer's website http://www.ihdd.ru. You can download MHDD as a CD image (file mhdd32verx.x.iso) or as a self-extracting floppy image. The same site contains a new version of the documentation for the program. By default, the program works with a hard drive connected to the secondary (Secondary) IDE channel as the first device (Master). It can also work with SATA or SCSI drives. The MHDD program has many functions. Here are just a few steps.
Getting disk information.
Scanning the disk surface.
Saving a disk image to a file.
These operations are united by the fact that they are not related to writing data to the disk being checked, that is, they are non-destructive. It is not worth doing anything else with the disk from which the user is going to recover information. The main task is only to assess the situation, and not to check the disk, which is the main purpose of the MHDD program.
1. Burn the program to a CD, and then boot your computer from it. The drive selection menu will appear on the screen (Fig. 2.6). Select the disk you want to examine and enter its number from the list. You can call up this menu at any time by pressing Shift+F3.
Rice. 2.6. Disc selection
2. After specifying a drive (for example, 3), press the Enter key. The program is ready to work with this hard drive. At the top of the screen are registers, or flags. Any IDE or SATA device should report "DRIVE READY" and "DRIVE SEEK COMPLETE", that is, the DRDY and DRSC flags should be highlighted. The BUSY flag signals that the drive is performing some operation, such as reading or writing.
You can get help about commands at any time by pressing the F1 key. Nevertheless, many people prefer to print out a list of commands in advance and put this sheet next to the computer - it's more convenient.
All commands are entered from the keyboard, case does not play a role. Entering any command is completed by pressing the Enter key. The Esc key is used to cancel or interrupt the execution of a command.
3. Enter the ID command to get disk information. Another command, EID, displays more detailed information (Figure 2.7).
Rice. 2.7. Disc Information
4. To scan the surface, press the F4 key or type the SCAN command and press the Enter key. A menu will appear where you can change some settings. By default, the start sector number is zero (start sector). The number of the final sector is equal to the maximum possible (the end of the disk). All functions that can change or destroy data on the disk (Remap, Erase Delays) are disabled by default. Press the F4 key again to start scanning.
MHDD scans drives in blocks. For IDE/SATA drives, one block is equal to 255 sectors (130,560 bytes). As scanning progresses, a block map is built on the screen (Fig. 2.8). To the right of it is the "legend". The shorter the block access time, the better. If there are problems when accessing the block, then the time increases, if an error occurs, then the corresponding symbol is displayed on the map.
Rice. 2.8. Surface scanning
Everything listed in the legend below the question mark (exceeding the allowed access time) are different variants of unreadable blocks. The interpretation of these errors is as follows:
UNC - Uncorrectable Error, unrecoverable error;
ABRT - Abort, command rejected;
IDNF - Sector ID Not found, sector identifier not found;
AMNF - Address Mark Not Found, address mark not found;
T0NF - Track 0 Not Found, it is impossible to find a zero track;
BBK - Bad BlocK, a "bad" block without a reason.
The main thing here is to understand that all these are the results of physical defects inside the HDA. It is important to decide how to save the data, not how to repair the hard drive. The caution when scanning is not to get carried away with diagnostics. However, the appearance of the map may suggest some conclusions.
Regularly repeating blocks with increased access time are the result of positioning the heads on the next cylinder. This is completely normal.
Randomly scattered blocks with various kinds of defects are a sign of the general degradation of the drive. Plates, bearings or heads are worn. Perhaps the hard drive was "beaten" or overheated.
A "spot" in the middle of which there are absolutely unreadable blocks surrounded by blocks with increased access time is a sign of an increasing defect on the wafer. It is necessary to urgently extract the image.
Strictly and regularly repeating identical groups of inaccessible blocks are a sign of a faulty head. If desired, you can even calculate this head based on the physical geometry of the disk. If the most important data is on the surface of the plate served by this head, the hard drive must be repaired under special conditions. Perhaps the plate is not completely scratched yet.
A useful feature is Acoustic Management. Noise, of course, does not excite the user. However, the noise level emitted when the heads are moved is reduced by reducing the speed of their movement. For a faulty hard drive, this may be a measure that can facilitate its operation.
1. Type the AAM command and press the Enter key. Here you can see the possible values of the parameter supported by this hard drive.
2. Enter the value corresponding to the quietest operation and press the Enter key. This will help the hard drive a little, especially the head block, for the duration of further manipulations.
On these steps, the diagnostics ends and data recovery begins. The MHDD program is capable of copying individual sectors or an entire disk to a file or set of files. Defective unreadable sectors are skipped by the program.
The TOF command copies the specified range of sectors (by default from zero to the last sector of this disk) into a single file. The image file size cannot exceed 2 GB. If the user decides to create a disk image larger than 2 GB, then it is better to use the ATOF command, since it can automatically divide images into separate files.
1. Type the TOF command and press the Enter key. The Fast Disk Image Creator prompt will appear (Figure 2.9).
2. Enter the number of the starting sector and press the Enter key.
3. Enter the number of the last sector and press the Enter key.
Rice. 2.9. Creating an Image with the TOF Command
4. Enter the path and file name of the image to be created. The name is arbitrary, and the file must be created on another physical disk.
5. Press the Enter key to start copying.
Upon completion of copying, you can turn off the problematic disk and no longer deal with it, but with the file - its sector-by-sector copy. This will protect the disk from further damage: if the hard drive starts to fail, every extra minute of work can add new bad blocks to the platters or completely ruin the damaged head. The user needs to start his communication with the problematic disk with copying, and postpone the diagnostics.
Which program to make a copy of is an open question. There is no definitive answer to it. The MHDD program and the very similar Victoria program create fewer problems when reading hard drives with numerous physical defects. Such problems may be the freezing of the program itself or the entire computer when trying to read some bad sectors. On the other hand, the R-Studio program is somewhat more convenient, especially since you still need to extract data from the image using this program. Conclusion: you can try using several programs.