How to use a low-level hard drive

 

How to use a low-level hard drive

Functions of Hard Disk low-level formatting Low disk formatting is the most thorough Initialization Method for the hard disk. After a low disk, all the data previously protected will be lost, so generally, the low disk is very undesirable, the ephemeral hard disk can only be used when necessary. There are two kinds of such so-called necessity: one is that before the hard disk is released, the hard disk factory will perform a low-level formatting on the hard disk; the other is that when the hard disk has a type of bad track, low-level formatting can mitigate or mask the problem. In the first case, we don't need to talk about it here, because the low-case work before the hard disk is delivered is only accessible to hard disk engineers. For common users, we don't have to consider this. In the second case, what type of bad track does it need to be low? Before explaining this critical issue, let's take a look at the type of bad sectors on the hard disk. In general, bad channels can be divided into physical and logical bad channels. Among them, the logical bad track is relatively easy to solve, which means that the hard disk is subject to long-term interference during writing, resulting in an ECC error. In terms of process, it means that when the hard disk writes data, it will re-combine the data with the ECC logic. Generally, the operating system will write 512 bytes, but in fact, the hard disk will write dozens of bytes more, and all these bytes must be verified and encoded using ECC. If the ECC calibration code calculated from the original bytes is different from the ECC calculated from the read bytes, in this way, an ECC error occurs, which is the cause of the so-called physical bad channels. As for the physical bad track, it is more lethal to the damage to the hard disk. It also has the difference between soft and hard physical bad track. The physical damage to the disk surface is hard, which cannot be repaired. When data writing errors are caused by external influences, the system will also consider it as a physical bad track, which can be used by some hard disk tools (such as detection and repair software provided by hard disk manufacturers) in addition, some hard disk Tools (such as the Data Lifeguard Tools of Western Data) can redirect to a good reserved sector to correct the error. Hard physical bad sectors cannot be repaired for these bad sectors. They are the most direct damage to the hard disk surface, so it cannot be repaired even if it is low or hard disk tools are used (unless it is very small damage, some tools can retain this part of the bad track for the purpose of solving ). If a logical or soft physical bad track appears on the hard disk, you can try to use low-level formatting to shield the bad track. However, it should be noted that blocking the bad track does not mean eliminating the bad track, the low-level hard drive can delete all partitions in the original hard drive, but the bad channels still exist. Blocking only hides the bad channels and prevents users from using these bad channels when storing data, this ensures the reliability of user data to a certain extent, but the bad track will spread with the growth of Hard Disk Partitions and formatting times. Therefore, the author does not recommend that users perform low-level hard disks. It is the best solution and the most thorough solution to solve the problem if you want to change the hard disks during the warranty period. If the hard disk is out of warranty and cannot be changed, try a low-case hard disk to prevent data loss caused by storing data to bad channels. In general, the tool is used for operating the hard disk with a low level. This will be detailed in the following sections. Here are some related topics. That is to say, there is a fundamental difference between the low-cell tool and the hard disk detection tool. The low-cell tool is used to perform the low-cell hard disk detection. The hard disk detection tool is generally used by hard disk manufacturers to detect hard disks, early detection of hard disk errors to remind users to back up important data or repair the hard disk. It is not used for low-level hard disks. Low-level formatting using Debug assembly language Low-level formatting allows you to destroy data in a hard disk. Therefore, be cautious before performing operations. There are many methods for low disk space, such as low disk space in CMOS or hard disk space in assembly language. The most common method is to use some tool software to perform low disk space, common low-level tools include lformat, DM, and various hard drive tools released by hard drive manufacturers. Assembly is a relatively low-level programming language, which can be very convenient to directly operate the hardware, and runs very efficiently, if the software system needs to directly operate the hardware, assembly languages are frequently used. Compilation can also be used for low-level formatting on the hard disk, which is more flexible than tools and software such as DM. The specific application is to use the debug program, and the specific operation is in the debug environment, call the low-level formatting program stored in the BIOS (this is also called by the low-level hard disk directly in CMOS ). There are usually three implementation methods: (1) directly call the low-level program in the BIOS ROM Low-cell programs are stored in bios rom of many computers. The storage address starts from the C8005H address. The specific operation is as follows: A: \> Debug -G C800: 0005 (// the information displayed on the screen (different BIOS versions may display different information). Press enter to prompt :) Current Interleave is 3 select new interleave or Return for current (// This requires the user to select a cross factor, press enter to take the default value 3, you can also enter a new cross factor value, generally, the cross factor of the hard disk is 3, so press Enter. The screen then prompts :) Are you dynamically locking ing the drive-answer Y/N t Press "Y" to begin formatting the drive C: with interleave 03 (// type "Y" and then start low disk space) Formatting ...... (// After the process is completed, check whether the track is processed) Do you want to format bad track-answer Y/N? If not, use "N" to answer the question. Screen Display: Format Successful, system will new restart, Insert Dos diskette indrive: Insert the system disk to drive A to perform partitioning, advanced formatting, and other operations to install the system. (2) Call the function interrupted by the INT for 13 h to perform a low-level hard disk The procedure is as follows: A: \> DEBUG -A 100 -XXXX: 0100 mov ax, 0703; (// The cross factor is 3) -XXXX: 0103 mov cx, 0001; (// 0 channels starting from 0 sectors) -XXXX: 0106 mov dx, 0080; (// disk C 0 track) -XXXX: 0109 INT 13 -XXXX: 010B INT 3 -XXXX: 010D -G 100 In this way, the hard disk is downgraded. (3) Call the function interrupted by the INT for 13 H. The 5-digit function interrupted by the INT 13 H is called on the hard disk, which only has 0 sectors and 1 sectors at a low level, without having to uncompress the entire hard disk, so that the low level can be completed within a short period of time. The procedure is as follows: A:> DEBUG -A 100 -XXXX: 0100 mov ax, 0500; (// call function No. 5) -XXXX: 0103 mov bx, 0180; (// set the buffer address) -XXXX: 0106 mov cx, 0001; (// 0 from the first sector of the track) -XXXX: 0109 mov dx, 0080; (// disk C 0 track) -XXXX: 010B INT 13 -XXXX: 010D INT 3 -E 0180 0 0 0002; (// write parameter) -G 100 Low-level formatting with DM The full name of DM is Hard Disk Management Program. It can manage Hard disks in low-level formatting, verification, and other ways to improve the efficiency of Hard disks. In general, DM has the following features: Hard Disk low-level formatting, partitioning, advanced formatting, hard disk parameter configuration, and other features. In actual applications, the dm tool is the same as A common doscommand (such as fdisk or format). Its command format is A:> DM [parameter]. The following values can be used for parameters: <> The/m dm software is manually entered. If this parameter is not set, DM runs automatically and runs INITIALIZE. PARTITIONG. PREPARAFION in sequence. <>/C dm software is executed in color mode, that is, it runs on a color monitor. <>/P dm manages hard disks in PC/XT mode. <>/A dm manages hard disks in PC/AT mode. <>/2 DOS 2.xx version. <>/3 DOS 3.xx version. <>/4 DOS version 4. XX (this parameter is available only for DM 5.01 ). <>/V dm runs in a way that can change the cluster length and root directory items. You can use either of the following methods to start an instance: 1. A:> DM (automatic mode. When initializing a hard disk, many parameters use the default value and almost do not require manual intervention ). 2. A:> DM (manual mode. Some parameters must be manually specified for formatting ). After the dm tool is started, you can select the appropriate operation as needed. Because it is stored in the form of a DOS user interface, it is very simple and clear to use. Other low-level formatting Methods In addition to the two low-level tools described above, there are many other low-level formatting methods. 1. Direct operation in CMOS If the motherboard supports this function, you can directly format the hard disk in CMOS. This method is very simple and convenient. Therefore, if possible, we recommend this method for low disk space. Specific Operation Method: Enter the CMOS setup according to the system prompt when starting the system (if it is award and other bios, a prompt will be prompted to press del to enter the cmossetup, if it is an Intel motherboard, usually press f2 to enter the CMOS setup), then select low formatted harddisk drive in the CMOS menu, and then perform the hard drive to be unformatted according to the program prompts, at the same time, you can answer some program questions to perform low-level hard disk formatting. 2. lformat.com program low-cell hard drive In addition to the DM tool, lformat.exe is a relatively simple program, which is a low-level formatting hard disk tool launched by maxcompute. After lformat.exe is run in dosstate, the program starts the warning interface. This screen indicates that if you use this tool, all data in the hard disk will be lost. Therefore, we recommend that you back up necessary data before running it, we recommend that you remove all other hard disks. If you forget to back up the data and want to exit the program, you can press any key except Y. If you are sure to press the "y" button for the hard disk. If "Y" is selected, the program requires the user to select a hard disk or perform low-level formatting on the current hard disk. Then, ask a few questions to start the hard disk low-level formatting process.