Hard disk use problem

Partition is essentially a format of hard disk. When we create the partition, we have set the physical parameters of the hard disk and specified the storage location of the master boot record (MBR) and the backup of the boot record. For file systems and other operating systems, the information needed to manage the hard disk is realized through the advanced format, that is, the format command.

Before installing the operating system and software, you need to partition and format the hard disk before you can use it to save all kinds of information. Many people think that since it is a partition, the hard disk must be divided into several parts. In fact, we can create only one partition to use all or part of the hard disk space. But no matter how many partitions we divide, and whether we use SCSI hard disk or ide hard disk, we must set the main partition of the hard disk as the active partition, so as to start the system through the hard disk.

[Edit this paragraph] Why partition the hard disk:

There is usually only one C disk when you buy a notebook.

1. When the system needs to be restored, the entire C disk, that is, the system disk, is formatted. If all the data is stored in the system disk, everything will go up in smoke.

2. Too many other things on the system disk will slow down the system.

3. Different types of data are packaged in corresponding disks, which are classified and easy to find.

4. After the hard disk is partitioned, the cluster size will also become smaller. A cluster is the smallest disk space that can be allocated for saving files. The operating system stipulates that a cluster can only put one file, so the space occupied by the file can only be an integer multiple of the cluster. And if the actual size of the file is less than a cluster, it will also occupy the space of a cluster. Therefore, the smaller the cluster, the higher the efficiency of saving information.

Extended partitions and logical partitions:

DOS and FAT file systems were originally designed to support up to 24 partitions on a hard disk, using 24 drive letters from C to Z respectively. However, the partition table in the master boot record can only contain up to four partition records. In order to solve this problem effectively, DOS partition command FDISK allows users to create an extended partition, and up to 23 logical partitions are established in the extended partition, and each partition is assigned a separate drive letter, which can be used as an independent physical device for computers. The information of logical partition is stored in extended partition, and the information of main partition and extended partition is stored in MBR of hard disk. That is to say, no matter how many partitions there are on the hard disk, the master boot record only contains the information of the main partition (boot partition) and the extended partition.

[Edit this paragraph] hard disk partition principle

After the hard disk is partitioned, there will be three forms of partition status; Namely, main partition, extended partition and non-DOS partition.

The non-DOS partition in the hard disk is a special partition form, which divides an area of the hard disk for another operating system, and it is the divided storage space of the operating system of the main partition. Only the operating system in the non-DOS partition can manage and use this storage area, and systems outside the non-DOS partition generally cannot access the data in this partition.

The main partition is a relatively simple partition, usually located in the front area of the hard disk, forming a logical C disk. The main boot program is a part of it. This program is mainly used to check the correctness of hard disk partition, determine the active partition, and hand over the boot right to DOS or other operating systems of the active partition. If this program is destroyed, it will not be able to start from the hard disk, but it can read and write from the soft area or the optical area.

The concept of extended partition is complex, and it is easy to confuse hard disk partition with logical disk. The fourth byte of the partition table is the partition type value. The normal bootable basic DOS partition value greater than 32mb is 06, and the extended DOS partition value is 05. If you change the basic DOS partition type to 05, you can't start the system, and you can't read and write the data inside.

If 06 is changed to a type that DOS doesn't know, such as efh, DOS thinks that the partition is not a DOS partition, and of course it can't read or write. Many people use this type value to realize the encryption technology of a single partition, and the partition can be restored to normal by restoring the original correct type value.

[Edit this paragraph] Common formats of hard disk partition:

1、fat 16

For computer veterans, this hard disk partition format is the most familiar, and most of us know and step into the computer threshold through this partition format. It adopts 16 bit file allocation table, and the maximum partition it can support is 2gb. It is the most widely used and supported disk partition format in the current operating system. Almost all operating systems support this format, from dos, win 3.x, win 95, win 97 to win 98, windows nt, win 2000/XP, and even the popular linux supports this partition format.

But the fat 16 partition format has one of the biggest shortcomings, that is, the actual utilization efficiency of hard disk is low. Because in dos and windows systems, the allocation of disk files is based on clusters, and a cluster is only allocated to one file, no matter how big this file accounts for the capacity of the whole cluster. Moreover, the size of each cluster is determined by the size of the hard disk partition. The larger the partition, the larger the cluster. For example, if the 1gb hard disk is only divided into one area, the cluster size is 32kb. That is to say, even if a file is only 1 byte long, it will occupy 32kb of hard disk space when it is stored, and all the remaining space will be idle, which will lead to a great waste of disk space. The larger the partition supported by fat 16, the greater the capacity of each cluster on the disk and the greater the waste. Therefore, with the increasing capacity of mainstream hard disks, this shortcoming has become more and more prominent. In order to overcome this weakness of fat 16, Microsoft introduced a brand-new disk partition format fat32 into win 97 operating system.

2、fat32

This format uses a 32-bit file allocation table, which greatly enhances its ability to manage disks and breaks through the limitation of 2gb per partition in fat 16. After using fat32 partition format, users can define a large hard disk as a partition without dividing it into several partitions, which greatly facilitates the management of the hard disk. Moreover, the biggest advantage of fat32 is that the capacity of each cluster in fat32 partition format is fixed at 4kb, and a partition does not exceed 8gb. Compared with fat 16, it can greatly reduce the waste of hard disk space and improve the utilization efficiency of hard disk.

At present, the operating systems supporting this disk partition format are win 97, win 98 and win 2000/XP. However, this partition format also has its disadvantages. First of all, due to the expansion of file allocation table, the disk partitioned in fat32 format is slower than the hard disk partitioned in fat 16 format. In addition, because dos system and some early application software don't support this partition format, the old dos operating system and some old application software can't be used after adopting this partition format.

3、ntfs

The Ntfs partition format is not familiar to ordinary computer users. It is the hard disk partition format of the network operating system windows nt, and users who use windows nt must deal with this partition format. Its obvious advantages are excellent security and stability, and it is not easy to produce file fragments in use, which is beneficial to the space utilization of hard disk and the running speed of software. It can record the user's operation, and by strictly limiting the user's authority, each user can only operate according to the authority given by the system, which fully protects the security of the network system and data. However, there are not many operating systems that support this partition format at present. In addition to windows nt, win 2000 just listed also supports this hard disk partition format.

However, unlike windows nt, win 2000 uses ntfs 5.0 partition format. The new feature of ntfs 5.0 is "disk quota"-administrators can limit the hard disk space that disk users can use; "Encryption"-When reading and writing files from disk, you can automatically encrypt and decrypt file data, etc. With the popularity of win 2000, computer users will gradually become familiar with this partition format.

4、linux

Linux operating system was the most popular operating system in it media last year. Because the system is free software, it can be loaded into the computer at almost no cost, so it has won many users. Its disk partition format is completely different from other operating systems, and there are two formats: one is linux native main partition and the other is linux exchange partition. The security and stability of these two partition formats are excellent. Combined with linux operating system, the probability of crash is greatly reduced, which can help us get rid of the nightmare that windows often crashes. However, at present, the only operating system that supports this partition format is linux, and users who are not interested in linux system can only sigh.

Through the above introduction, I think you must know something about the common hard disk partition formats. Then, according to the operating system that needs to be installed, quickly determine the partition format of the hard disk.

The hard disk must be partitioned before it can be used. After partitioning the disk, the next step is to format the hard disk, which must be formatted before it can be used.

Formatting is to create tracks and sectors on the disk. After tracks and sectors are created, computers can use disks to store data.

Under Windows and DOS operating systems, there are formatters to format. However, once the hard disk is formatted, all the data in the hard disk will disappear! So before this action, it is necessary to determine whether the data in the disk is still needed, and if so, back it up separately.

5.exFAT

ExFAT (Extended File Allocation Table File System) is a file system suitable for flash memory introduced by Microsoft in Windows Embeded 6.0 (including Windows CE 6.0 and Windows Mobile). For flash memory, NTFS file system is too complicated, and exFAT is more suitable.

Compared with the FAT file system, exFAT has the following advantages:

? Enhanced interoperability between desktop computers and mobile devices.

? The maximum file size is16eb (2 305 843 009 213 693 952 bytes, i.e. 16M TB, 1TB= 1024G).

? The cluster size can be as high as 32MB.

? The remaining space allocation table is adopted to improve the remaining space allocation performance.

? The maximum number of files in the same directory can reach 65,536.

? Support access control

? Support TFAT

Flash drives using this file system do not support Windows Vista ReadyBoost. Windows Vista SP 1 supports this file system.

Please note: exFAT is only a compromise solution, which only applies to USB flash drives.

It should be strictly noted that this partition is only supported by vista and cannot be used by other systems. Xp can support this format by replacing the driver file, but it can only be read and written, not formatted.

[Edit this paragraph] Using spatial calculation

When the hard disk is just partitioned, each partition will have more than 60 m of used space (I found it on my own WDC WD640 1ALS-00L3b2, and I don't know if other brands and models of hard disks have the same rule. Please criticize and correct me if there is any discrepancy). What are the rules?

My research is summarized as follows:

The used space of n GB hard disk is (6757 17 12+32768 * n) bytes 1024 bytes.

Where 67571712 = 226+218+217+216+212.

That is, (64.44140625+0.03125 * n) MB 0.00009765625 MB (the error is very small, almost negligible).

The following data are all surplus values.

(that is, when n

( 18G & lt； N & lt49 66m)

(50G & ltn & lt8 1G 67M)

(82G & ltn & lt 1 13G 68M)

( 1 14G & lt； N<145g 69m)

( 146g & lt； N<177g 70m)

( 178g & lt； N & lt209 7 1 m)

(2 10G & lt； n & lt24 1G 72M)

(242G & ltn & lt273 73m)

(274G & ltn & lt305G 74M)

[Edit this paragraph] hard disk partition integer G integer algorithm

(The most accurate integer division from 1g to 200g) (R) The usual integer division algorithm is M=(G- 1)X4+ 1024*G, where m is the input size during division. For example, if the partition we need is 10G, then (10)

A hard disk generally has 255 heads and 63 sectors (to verify here, there are generally not so many heads, but the result behind is correct), so the size of each cylinder is:

5 12 bytes x255 x63 = 8225280 bytes =7.84423828 125 M.

If it is to be divided into 4G, it is 4× 1024M=4096M.

The required number of cylinders is 4096 ÷ 7.438+025 = 522.8+066.

The integer is 523 cylinders.

The score m is 523× 7.845438+025 = 4102.4338+009375m.

No matter how many decimal places you enter 1, that is, 4 103M, windows thinks it is 4.00G (here is a question, why is 4 103M recognized by windows as an integer g? )

This method is very common in NTFS and FAT32.

The most accurate integer division is from 1g to 200g g.

1G : 1028M

2G:2056

3G:3075

4G : 4 103M

5G : 5 123M

6G : 6 150M

7g: 7170m

8G : 8 198M

9G : 92 17M

10G : 10245M

15G : 15367M

20G : 20482M

25G : 25604M

30G : 30726M

35G : 3584 1M

40 grams: 40,963 meters

45G : 46085M

50G : 5 1208M

55G : 56322M

60G : 6 1444M

65G : 66567M

70G : 7 168 1M

75G : 76803M

80G : 8 1926M

85G : 87048M

90G : 92 162M

95G : 97285M

100G : 102407M

1 10G: 1 12644m

120G : 122888M

130G : 133 125M

140G : 143362M

150G : 153606M

160G : 163843M

170G : 174088M

180G : 184324M

190G : 19456 1M

200 grams: 204806 meters

Although I have read the article, I still don't understand ~ what is the principle of hard disk partition? [For example, whether to take the number of full cylinders of a partition (disk partitions are upgraded one by one by sectors and columns, because this is the actual reading and writing work of the disk), the storage size of a cylinder = number of sectors * number of heads * sector size; For example, to divide disk C into whole G, a non-integer number of cylinders is needed according to the storage capacity of cylinders, such as 100.5. How many cylinders does disk C actually occupy after partition? 10 1? Or 100.5, then the spare storage space behind the cylinder of 10 1 is reserved for the next disk? If the whole column number is taken, the actual size of drive C will exceed the original whole G, so how can windows identify it as a whole G? ]

Is the size entered when partitioning the same as the size principle recognized under windows? The answer should be no, what is the principle? Is the hard disk partitioned by columns, tracks or sectors? Is the separated C disk G, a whole column, a whole track or a whole sector ~ ~ ~

[Edit this paragraph] How to use DM to partition the hard disk

choice menus

1. Simple disk installation

Hard disk automatic partition option is an automatic partition option for DM. After selection, DM will automatically partition according to the hard disk capacity. This function is more suitable for novices.

Tip: With automatic partition, the system will not prompt the user to partition the hard disk, but it is the default. This option is not recommended.

2. Advanced options

Advanced option, which is a manual partition option provided by DM. After selection, a secondary submenu will appear:

Manually partition the secondary submenu

There are three options in the secondary sub-menu. The functions of these three options are: advanced disk installation; Maintenance options; Upgrade disk manager (modify and upgrade hard disk driver ONTRACKD. SYS, and identify the large-capacity hard disk).

Second, the actual division of labor.

1. Select the advanced disk installation option, and DM will automatically search the hard disk. After searching, you will be asked which partition format to use.

2. Select partition: Because you want to set the size of each partition yourself, you ignore the first two options of automatic partition, so you can directly select option (c) to customize manual partition of hard disk.

3. Set the size of each partition: enter the size of the main partition first, and then enter the size of each logical partition in turn (please note that unlike Fdisk, there is no option to create an extended partition). After the partition is completed, select the "Save and Continue" option, and then click "OK" to save the setting results twice in succession. If you are not satisfied with the capacity of any partition, you can press Del to delete it and re-establish it.

4. Complete formatting partition

After saving the partition information, press ALT+C to continue the operation. The system will prompt whether to quick format each partition of the hard disk, and select Y to quick format each partition.

After all the operations are completed, you will be prompted to restart your computer (the settings will not take effect until you restart).

Tip: Please note that after the formatting work is completed, please wait for the system prompt to restart before restarting the computer. Otherwise, the partition may be invalid or even lost.

[Edit this paragraph] The solution of changing hard disk partition into RAW format

Step 1: First, switch to the classic view in the control panel, find the management tool, double-click to open it, then double-click to open the local security policy, click the plus sign in front of the local policy, then click the security option, find the item "Network access: sharing and security mode of local accounts" in the right window, and then set the security setting behind it to "guests only-local users only".

Step 2: Open My Computer, right-click the partition in RAW format, click Properties, find the "Security" tab in the pop-up properties dialog box, delete the garbled code in the "Group or User Name:" list box, and then add the local user.

Tip: If you right-click the partition and there is no Security tab in the pop-up properties dialog box, you can open My Computer, click Tools-Folder Options-View, and uncheck the box in front of Use Simple File Sharing (Recommended).

I don't know much about this. I found it for you. I don't know if it will help you.