How hard disk partitioning works

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I. Hard Disk partitioning for your hard disk, the first thing you need to do is partitioning. Whether the hard disk partition is reasonable directly affects the convenience of future work and data security. The most common Partition Table error is also the most serious disk error. Different errors may cause different losses. If there is no active partition flag, the computer cannot start. However, you can read and write the hard disk after the drive or Drive boot system. You can use fdisk to reset the active partition to repair the disk. If a partition type is incorrect, the loss of a partition may occur. After hard disk partitioning, three forms of partition status are formed: Primary partition, extended partition, and non-DOS partition. Non-DOS partition (non-DOS partition) in a hard disk is a special partition form, which separately divides one area of the hard disk for use by another operating system, for the operating system of the primary partition, It is a partition of storage space. Only the operating system in a non-DOS partition can manage and use this storage area. systems outside the DOS partition generally cannot access the data in this partition. The primary partition is a relatively simple partition, usually located in the first area of the hard disk, forming a logical C disk. The main Bootstrap program is a part of it. This program is mainly used to check the correctness of the hard disk partition, determine the active partition, and hand over the boot permission to the DoS or other operating systems of the active partition. If the program is damaged, it cannot be booted from the hard disk, but the hard disk can be read and written after the software or optical area. The concept of extended partitions is complex, which can easily lead to confusion between hard disk partitions and logical disks. The fourth byte of the partition table is the partition type value, normally, the basic DOS partition value larger than 32 MB is 06, and the extended DOS partition value is 05. If you change the basic DOS partition type to 05, the system cannot be started and the data in the partition cannot be read or written. If you change 06 to DOS, for example, EFH, DOS considers that the partition is not a DOS partition and cannot be read or written. Many people use this type of value to encrypt a single partition and restore the original correct type value to restore the partition to normal. There are other data in the partition table used to record the start or end address of the partition. Damage to the data will lead to confusion or loss of the partition and generally cannot be restored manually. The only method is to re-write the data in the backup partition table, you can also obtain partition table data from other hard disks of the same type and with the same partition status. Otherwise, other data will be lost permanently. The microcomputer operating system only reserves 64 bytes of storage space for the partition table, and the parameters of each partition occupy 16 bytes. Therefore, the operating system can only store data in four partitions, in actual use, the four logical disks often cannot meet the requirements. We often say that the hard disk expansion partition is just a pointer to the next partition. This pointer structure will form a one-way linked list. Therefore, the loss of the Logical Disk may occur if a problem occurs in the one-way linked list. The birth of the ghost system backup and restoration software provides us with great convenience, such as operating system restoration and file backup, provides us with secure and Fast File spare parts and system installation solutions. However, we often encounter some problems when using the Ghost Software for system restoration, when you use ghost to restore the system, the drive letter is disordered and the hard drive partition cannot be found. In this case, let's simply summarize the faults and solutions of this system restoration, I hope my friends who have encountered the same problem will be helpful. Fault Phenomenon: My friend's computer is relatively old, so I installed Windows 98 and Windows 2000 dual operating systems. After 98 was used for about half a year, the recycle bin suddenly failed to work normally, so a friend decided to use ghost to restore the system. A friend's computer hard drive uses a 40 Gb product of Seagate's 7th generation. In order to facilitate management, it is divided into four areas: C, D, E, and F, among them, Windows 98 is installed in the system partition drive C, Windows 2000 is installed in partition D, and partitions e and f store a large amount of important data. Due to a problem with the 98 system, the author enters WIN98 and runs ghost to restore the system. When the restore process runs to 40%, the system displays a blue screen and crashes, after the machine is restarted, the system fails to boot properly. Fault Analysis and troubleshooting methods: Before Fault Analysis and troubleshooting, let's take a look at the detailed configuration of this computer: The processor uses Intel saiyang 1.1 GB, 256 m ddr266 memory (single-stick ), the motherboard is Intel 915g original motherboard, integrated graphics card, and the computer is installed with a DVD-ROM drive and a modem. As there is a large amount of important data in the partitions E and F of the hard disk, the partitions E and F of the hard disk cannot be damaged in case of a fault. According to the above fault phenomenon, we can see that the problem mainly occurs on the hard disk, so the author enters the BIOS after the boot and finds that the hard disk and its capacity can be detected normally. So I use a boot disc to boot the system into DOS, and then I can see the C disk, but I cannot read the data in any way. Therefore, "format C:/s" is used to format the C disk, but it cannot be started normally after it is started! So I thought of using fdisk to check the partition of the hard disk, but found that there is only one partition, and still extended partition, d, e, f partition all disappeared inexplicably. In order to protect data security on partitions E and F, I gave up the idea of using fdisk to reconstruct partitions. My friend's computer is often used to access the Internet, so I began to suspect that the hard disk is infected with a virus. Therefore, kv3000 anti-virus software was used to completely disinfect and detect the hard disk under DOS. The final detection result was that there was a problem with the partition table of the hard disk, so kv3000 was used to fix the hard disk partition table. After the repair is successful, use fdisk to view the partition information of the hard disk. The result shows that the C and D partitions are successfully found, and the E and F partitions are still not detected, but the surprise is that it correctly shows the capacity of the C and D partitions and the total capacity of the hard disk. However, the two partitions E and F have not been found to concern me very much. All the important data on the hard disk is on these two partitions. If the partition breaks down the data, it will be completely lost. Now you have no idea, and now you have found the system C partition, you may want to install the operating system first, and then I will put the Win98 installation disk into the optical drive, we plan to install the Win98 System in the C partition. The installation process is still quite smooth. After the boot through the optical drive, the Win98 installation interface is smoothly displayed. First, check the partition drive C. Everything is normal, but a problem occurs during disk D check, in any case, normal detection cannot be completed. What is the reason for this? Is the win2000 system on d partition a strange? As a last resort, I used the format command again to reformat the D disk. If the installation of Win98 fails, simply install Win2000. Therefore, after re-formatting the D disk, the author puts the Win2000 installation disk into the optical drive and starts the new Win2000 installation from the optical drive. The installation process was smooth, and the system checked the C, D, E, and F partitions normally during installation. After the installation is complete, the system starts smoothly and enters the Win2000 operating system. So I opened my computer to check the partition of the hard disk, and the results still failed to detect drive E and drive F, what is the reason for this? When installing Win2000, what are the four partitions? So I quit the Windows operating system and run fdisk to view the partition of the hard disk. It is the same as that in the Windows operating system, and there are still only C and D disks! At this time, I suddenly thought of the hard disk management tool "partition magic", this tool can be executed in the Windows operating system. So I started the computer for windwos
2000, use "partition magic" to check the hard disk. when checking the D disk, many bad clusters are prompted, but they are fixed one by one. After the repair is completed, I opened my computer again. A miracle occurred. The four partitions C, D, E, and F were quietly lying in my computer. I checked the data on drive E and drive F, which was also intact, to some extent, faults caused by ghost system restoration can be completely repaired. During work, regular data backup is an important way to ensure timely data recovery after system crash and hard disk damage. Therefore, we should develop a good habit of backing up data frequently at work. In addition, you must learn how to save the hard disk when the hard disk fails, or extract useful data from the bad area to minimize the loss.
1. The system does not recognize that the hard disk cannot be started from the hard disk, and cannot be started from disk A to drive C. The existence of the hard disk cannot be found by using the automatic monitoring function in CMOS. Most of these failures occur on the connection cable or IDE port. The failure of the hard disk itself is unlikely. You can re-plug the hard disk cable or change the IDE port and cable to conduct replacement tests, you will soon find the fault. If the new hard disk is not accepted, a common cause is the master-slave jumper on the hard disk. If an IDE hard disk is connected to two hard disk devices online, the master-slave relationship should be clearly defined.
The method is relatively simple. The fdisk with a higher DOS version is the most convenient. When the fdisk with parameters/MBR is running, the primary boot program of the hard disk will be directly replaced (overwritten. In fact, the Main Boot Sector of the hard disk is created by this program. fdisk. EXE contains the complete Main Boot Program of the hard disk. Although the DOS version is constantly updated, the Main Boot Program of the hard disk has not changed, from DOS 3. for DoS from X to ipvs 95, you only need to find a DOS boot disk to start the system and run this program to fix it.
Ii. Whether the hard disk type in CMOS is correct caused by CMOS directly affects the normal use of the hard disk. Currently, all machines support the "Ide Auto Detect" function to automatically detect the hard disk type. When the hard disk type is wrong, sometimes the system cannot be started, sometimes the system can be started, but a read/write error occurs. For example, if the hard disk type in CMOS is smaller than the actual hard disk capacity, the sectors behind the hard disk cannot be read or written. If the disk type is multi-partition, individual partitions will be lost. There is another important cause of failure. Because the current ide supports the Logic Parameter type, the hard disk can adopt "normal, LBA, large" and so on. If data is installed in normal mode, changing to another mode in CMOS will cause a read/write error on the hard disk. Because the ing relationship has changed, the original hard disk location cannot be read.
Iii. Boot failure caused by the main boot program the Main Boot Program is located in the primary Boot Sector of the hard disk. It is mainly used to check the correctness of the hard disk partition and determine the active partition, this tool is responsible for handing over the boot right to the active partition's DoS or other operations. Click "Browse" to select the file to be restored. Click "Repair" to bring up the "Save as" dialog box, select the path to save the repaired file, and click "save" to view two articles "Hard Disk Adventures" and "new mine law" On the website recently ", this article describes how the author solves the hard disk of a logical bomb. The author of the first article, the Holy Church angel, black crystal, adopts the method of live plugging, the idea is novel, heroic and dry cloud, for my life has not seen, deeply sigh. Zhou.com, author of the "New Law of mine clearance", uses a pure software solution to modify system file I/O. sys is intended to start with a "disease". Although the method is good, the combined use of debug, fdisk, pctools, and ultraedit is too troublesome, so that general users are discouraged. I encountered this problem a year ago. At first I thought it was a hard disk "sacrifice", And I purchased a new disk. Half a month later, a day of Internet access suddenly crashed. Restart, self-check is normal, start the system..., there is no movement in one minute, and "sacrifice" again, my God! After you have calmed down, think about it. It is impossible for both hard disks to break down. Otherwise, Seagate is too bad (both hard disks are Seagate ). I think again it's all about faults that happen after the Internet crashes. Is it a "trick? The floppy disk cannot be started either!
What should I do? After several days of hard work, we finally found a simple, convenient, and reliable solution. Everything you need is simple, compatible machine (most of the domestic brands can also) One, DM software (when buying a hard disk to send or go online down ). Next let's start: Step 1: copy the DM to a good hard disk (if there is one, use a floppy disk if there is none ). Step 2: connect to the bad hard disk, start the device, and enter CMOS. In addition to the hard disk, set the other ides to none (key), save, and start the device. Step 3: Go to DOS, run DM, select bad disk, partition format, OK, and start. Step 4: Enter CMOS to identify the hard disk or set it to auto. Save and start it. Well, it's easy. For netizens who are used to using DM partition to Format hard drives, it's just a bunch of dishes. It should be noted that this method is generally not available for original computers such as IBM and HP, because the second step cannot be completed, and the system cannot be started. The principle of this method is that DM does not rely on the hard disk identification installation method set by BIOS, I believe that netizens all know how to install a large-capacity hard disk on an early system that cannot identify a large hard disk. 4. The Partition Table error caused by Partition Table errors is a serious hard disk error, different errors may cause different losses. If there is no active partition flag, the computer cannot start. However, you can read and write the hard disk after the drive or the Drive boot system. You can use fdisk to reset the active partition for repair. If a partition type is incorrect, the loss of a partition may occur. The fourth byte of the partition table is the partition type value. Normally, the basic DOS partition value larger than 32 MB is 06, and the extended DOS partition value is 05. Many people use this type of value to encrypt a single partition and restore the original correct type value to restore the partition to normal. The partition table contains other data used to record the start or end address of the partition. Damage to the data will cause confusion or loss of the partition. The available method is to re-write the data in the backup partition table, you can also obtain partition table data from other hard disks of the same type and with the same partition status. The recovery tool can use tools such as nu for easy operation. Of course, you can also use DEBUG for operations, but the operations are cumbersome and risky. 5. The failure of a partition effectively marks an error. An important part still exists in the primary Boot Sector of the hard disk, that is, the last two bytes: "55aa ", this byte is a valid identifier of the slice. When the disk is started from a hard disk, floppy disk, or disc, the two bytes are detected. If the disk exists, the hard disk exists. Otherwise, the hard disk is not recognized. This can be used for the encryption technology of the entire hard disk, and the debug method can be used for recovery. In addition, when the DOS boot sector does not have a boot flag, the system starts to display "mmissing Operating System ". The convenient method is to use the following common repair methods for the dossystem.
6. startup failure caused by the DOS boot system consists of the DOS Boot Sector and the DOS system file. System files mainly include IO. sys, msdos. sys, command. com, where command. com is a DOS shell file, which can be replaced by other similar files, but is a required file for DOS Startup by default. In Windows 95, msdos. sys is a text file that is required to start Windows, but does not need to be used when only DOS is started. When a DOS boot error occurs, you can use sys
C: The Command Transmission System can fix the fault, including the Boot Sector and system files. 7. read/write failures caused by the fat table records the storage address of the hard disk data. Each file has a set of fat chains to specify the cluster address. Corruption of the fat table means the loss of file content. Fortunately, the DOS system provides two fat tables. If the current fat table is damaged, the second fat table can be replaced. However, because the length of the fat table of disks of different specifications and the address of the second fat table are not fixed, you must find the correct position in the fix, some tool software such as Nu has such repair functions and is very convenient to use. Debug can also be used to achieve this operation, that is, use its m command to move the second fat table to the first table. If the second fat table is damaged, the hard disk cannot be restored to its original state, but the file data is still stored in the data area of the hard disk, you can use the chkdsk or Scandisk command to fix the issue *. chk file, which is the loss of the sector data of the fat chain. If it is a text file, you can extract the complete or part of the file content from it.
System. If the program is damaged, it cannot be booted from the hard disk, but the hard disk can be read and written after being started from the soft drive or optical drive. 8. Directory table damage the boot failure directory table records the file names and other data in the hard disk. The most important one is the starting cluster number of the file. Because the directory table does not have the automatic backup function, a large number of files will be lost if the directory is damaged. One way to reduce the loss is to use the chkdsk or Scandisk program to restore the method, search for * from the hard disk *. chk file, because the directory table is damaged, only the first cluster number is lost, each *. the chk file is a complete file. Change it to the original name to restore most files. 9. data recovery when partitions are deleted by mistake. After fdisk is used to delete hard disk partitions, data on the hard disk disappears completely. If data is not formatted, the disk is displayed as an invalid drive. If you understand how fdisk works, you will know that fdisk only rewrites the content in the primary Boot Sector of the hard disk (0-sided 0-Sector 1-sector). Specifically, it deletes the partition table information of the hard disk, the data in any partition on the hard disk has not changed. You can recover the original partition and data by following the preceding solution to partition table errors. If you have already formatted the partition, you can restore the partition data in the following way after the partition is restored.
10. Restoring accidentally formatting hard disk data in a high DOS version. By default, the format formatting operation creates disk information for restoring formatting, in fact, the DOS Boot Sector, FAT partition table, and directory table of the disk are copied to the last several sectors of the disk (because the following sectors are rarely used ), the content in the Data zone has not changed at all. In this way, you can run the unformat command to restore it. In addition, DOS also provides a miror command to record the information of the current disk for formatting or restoration after deletion. This method is also effective.
The biggest risk of a computer office is data loss. The result of hard work is often nothing but a small mistake. Therefore, mastering a certain degree of data recovery knowledge is a technical quality that every computer office staff must possess. However, what is data recovery and how can it be restored after data loss? Do you know how to deal with data recovery under various questions? Q: The last time I sorted out the system, I accidentally deleted a system file, which caused the computer to run abnormally. Is there any way to restore it? A: If a file is deleted to the recycle bin, you can use the restore function of the recycle bin to restore it: Open the recycle bin and select the deleted file; click "Restore Project" in the "recycle bin task" column. If the deleted file cannot be found in the recycle bin, you can also restore it by clicking "System Restore". The operations are as follows: click "Start> program> attachment> System Tool> System Restore ", open the "System Restore" Wizard. In the wizard interface, select the "Restore my computer to an earlier time" check box and click "Next" to continue; in "calendar", select the System Restore point. The Restore point should be the date before the file is deleted, and click "Next" to continue. Confirm the Restore Point and click "Next ", after the system is restarted.
Q: due to sudden power failure, the edited Word documents are not saved in time. How can I retrieve the word data that has not been saved? A: In the Word 2002 or Word 2003 versions, when you encounter a sudden power failure, start the system again and open Word, the system will automatically pop up a list, find the unsaved file, open it, and save it again. In the future, when editing important Word documents, set the Automatic save function so that the system can save it at a certain time, which reduces the risk. Q: Hello! When I perform the "open" operation on one of my Word documents, a prompt of file damage is displayed, and no content is displayed. How can I restore it? A: If the Word document is damaged, you can use the word file converter to restore the document from any file. The procedure is as follows: open or create a new word document. Click the "option" command in the "Tools" menu, in the displayed "options" dialog box, select the "General" tab, select the "Confirm conversion when opening" check box, and click OK. Click the "open" command in the "file" menu, select "Recover text from any file" in "file type", locate "search range" to damaged Word documents, and click "open. Q: When I use a USB flash drive, some important files on the USB flash drive may be lost due to incorrect plugging operations. Can I still remedy this problem?
A: You can use the "finaldata" software for data loss on the USB flash drive. After running the software (fianl data download, click the open command in the File menu. In the select drive dialog box, select the drive letter and click OK to start scanning, select all files to be restored in the "Lost directory" or "lost files". Click the "Restore" command under the "file" menu to bring up the "Select Directory save" dialog box, confirm the Save path and click "save. Q: to ensure data security, I burn some important files to a CD. However, I do not know whether the disc is worn out or the cause of the burning quality. Recently, a disc has encountered a phenomenon where data cannot be read. Is there any way to restore these files that cannot be read?
A: This is really helpless, but you can try to use badcopy to fix it. It not only restores damaged files, but also restores lost files (download badcopy Pro) after the software is running, select CD-ROM in recovery source to enter the recovery wizard; in the first step dialog box of the wizard, click recovery mode drop-down box, you can select "Save damaged files" and click "Next" to continue. Enter the folder of the files to be repaired, select the files to be repaired, and click "Next" to start the repair; after the file is repaired, click "Browse" to select the path to save the file after the repair, and then click "Next. Q: due to a friend's misoperations, I formatted the entire edisk. Can I restore the files stored on the edisk?
A: You can use the software to recover the formatted partitions. After running the recover my files (recover my file download) software, click "Open disk drive" in the shortcut toolbar, select the disk partition to be restored, select the file to be restored after scanning, and click "save" in the shortcut toolbar, select the drive to save the file. Q: I accidentally opened an email with a "cover letter" virus, causing damage to some files in the system. How can I recover the damaged data? A: First, click here to download the "cover letter file restoration tool ".