Disk Management Is a Small Tool in Computer [MiniTool Wiki]
Disk Management is a routine task when you use computer. It is provided for users in the form of a set of disk management applications, which lie in the "Computer Management" console. Disk Management includes error routine, Disk Defragmenter and Defraggler.
After we know the cause of disk fragmentation, we also need to get to know how disk reads and writes when program runs. Generally, when a program runs, head of disk driver will search the files which are necessary to run the program. Then, it reads data. And finally, it does reading processing - transfers data to disk cache and memory. Searching time is called average seek time (milliseconds) in hard disk performance index. Average seek time of hard disk is less than 9.5ms. If the relevant documents of application can be placed in continuous disk space, the search time of head will be reduced a lot.
Time required for reading data of sectors under the head is only one fifth of that required for moving head to another place and then reading the same data. When disk is read, system will check whether the data are in the cache. If the data are in the cache, they will be read directly. If not, disk will be accessed, which is also called reading disk. When the same data need to be read for several times, cache plays a great role.
But if a file is read for the first time, cache can do nothing. So, searching time and reading time largely affect the efficiency of program execution. Of course, all of the above description can be summarized as pictographic explanation of teacher at school: let's set "_" as the space left after files are deleted. And 1 represents disk file.
If the present messy disk space is "_ 1 _ 11 _ 1 _", this space can't be loaded if you want to copy files 111 into it. You can only insert fragmented file 111 into the space. Of course, this reduces the reading efficiency of files. But if the disk is defragmented, the place will become "1111 ——". Then the files 111 can be copied into the space in the most orderly way.
In fact, as long as there is no change in the hardware manufacturing process and the physical medium, the above principle absolutely exists and is available no matter how much disk performance is increased. These simple problems sometimes may not be noticed by users. They may think that their hard disk is in good state. And they may not perform disk defragmentation. So, it's no doubt that we should regularly defragment hard disk.
Actually, in most cases, regular disk defragmentation reduces wear of hard disk. Anyway, it's easier for head to read files from 1 than from 8. Therefore, service life of a disk, which is defragmented every two or four weeks, is longer than that of another disk which is never defragmented.
Actually, disk fragmentation should be called file fragmentation, because files are separately saved to different locations of disk rather than continuously saved to contiguous clusters of disk. When physical memory needed by applications is not enough, OS will produce temporary swap files on hard disk. Then OS makes virtual memory by using hard disk space occupied by the files. Virtual memory management program will frequently read and write on hard disk. This may produce large amounts of fragmentation. This is the main reason for producing disk fragmentation.
There are also other reasons. For example, temporary files produced when you use IE browser to browse information or setup for temporary files directory also results in a lot of fragmentation produced on hard disk. In general, file fragmentation doesn't cause problems in system. But too much file fragmentation will make system seek back and forth when it reads files. This will degrade system performance. What's worse, service life of hard disk may also be shortened. In addition, too much disk fragmentation may cause loss of files saved on disk.
Generation of Fragmentation
In disk partition, files will be separately saved to different locations on hard disk rather than continuously saved to contiguous clusters on the disk. In the process of file operations, Windows system may call virtual memory to synchronously manage program. This will lead to individual programs frequently reading and writing on hard disk, which may result in disk fragmentation.
Large Windows is made up of many modules. If you want to be proficient in Windows, you have to start from the module. In Windows, "Control Panel" is a very important module. For computer freshmen, it's quite necessary to know Windows operations by knowing "Control Panel" first.
"Disk Management" is an important component of "Computer Management" in "Control Panel". You can list all disks and perform operations to each disk partition by using Disk Management. For computer freshmen, disk management tool can help them complete some important operations without using third party tool. For example, drive letter chaos appears when two hard drives are installed on computer. You can use Windows built-in Disk Management to directly change drive letters.
If CD-ROM drive and hard disk drive are not normal (CD-ROM drive is D:, but hard disk drive is C:, E:, F: and G:), drive letter D: and G: are required to be interchanged with each other. It's a little difficult to change Windows disk drive letter. If you operate incorrectly, system stability may be affected. Of course, once you learn to use Windows built-in Disk Management to change drive letter, then you can easily solve the problem of replacing drive letter.
Step 1: In Windows, "Disk Management" must be used to change drive letter. Where can we find this tool? You can click "Start - Control Panel - Administrative Tools - Computer Management". At this time, a "Computer Management" window will pop up as shown in the above screenshot. You can click "Disk Management" from the left pane. And you'll see all disks on the computer in the right pane.
Step 2: Users should know that because CD-ROM drive letter is interchanged with hard disk drive letter, hard disk drive letter must be replaced with a spare letter first. Then, we should directly replace the CD-ROM drive letter with the previous letter used by hard disk. Finally, we can replace hard disk drive using a spare letter with the previous letter used by CD-ROM.
We will do operation on hard disk according to this way. Here we right click hard drive G:. Then we choose "Change Drive Letter and Paths for G: ()" in the pop-up menu. Next, we click "Change" in the pop-up dialog box. After "Change Drive Letter or Path" dialog box pops up, we choose "Assign the following drive letter". And then we click right drop-down button to choose a spare drive letter, such as O:. Now, we have successfully changed the drive letter of hard drive G:.
Step 3: The next step is to change CD-ROM drive letter D: to G:, whose operating way is similar to that of hard drive. You can right click CD-ROM drive letter D: and choose "Change Drive Letter and Paths for D: () - Change – Assign the following drive letter" from the pop-up menu. You may choose P: from drop-down list and then click "OK". Then, you can do the same operations. You may replace hard disk drive letter O: with D: and then restart computer. Now, you've successfully interchanged CD-ROM drive letter with hard disk drive letter.
Generally, if you need to resize disk partition, you may achieve this with the help of Disk Management.
You should open "Disk Management" option and right click drive M:. Then, you choose "Delete logical drive" and click "Yes" in the dialog box. "Free space" will show on Drive M: .
You can right click "Free space" and choose "New Logical Drive" to open "New Partition Wizard" dialog box. Then you click "Next" to open "Select Partition Type" dialog box. You choose "Logical drive" and click "Next". You have to input value of disk partition size in "Partition size in MB" text box in "Specify Partition Size" dialog box. Then, you choose drive letter and path and click "Next" to format partition.
If you want system to recognize the new partition, you have to perform formatting partition. In "Format Partition" dialog box, system prompts: "Formatting will erase all data on this volume. To format the volume, click OK. To quit, click Cancel". You click "OK" to start formatting.
You can divide remained disk space into another partition according to your needs in the same way.