Relationship between system page files and virtual memory

The tutorial for helping customers (www.bkjia.com) first introduces the page files in windows: page files refer to the hard disk space used by the operating system to build virtual memory. To sort out the page file, first move the page file from the original drive to another drive, then sort the original drive, and finally move the page file back to the original drive, at this time, the page files will be stored in the continuous disk space.

Specifically, in windows operating system (Windows 2000/XP) pagefile. sys is a system page file (also known as a virtual memory file). Its size depends on the number of opened programs and the minimum size of the page file you set, is constantly changing, sometimes only a few dozen M, sometimes more than 600M.

Some large software consumes a large amount of memory and also opens up a portion of the hard disk space as a buffer. The entity of this part of the hard disk space is the page file created by the software, such as Photoshop. This design can relieve the pressure on the system's scheduling memory and improve the software running speed.

If the computer lacks the random access memory (RAM) required for running programs or operations, Windows uses virtual memory for compensation.

We all know that although the hard disk is not as good as the memory in terms of running speed, the memory in terms of capacity cannot be compared with the hard disk. When running a program requires a large amount of data and occupies a large amount of memory, the memory will be "full" and the data temporarily not used will be put into the hard disk, the space occupied by the data is the virtual memory. Now we also understand why the size of pagefile. sys changes frequently.

In the windows (XP) directory, there is a file named pagefile. sys System File (Win386.swp under Windows 98), its size is often changed by itself. When it is small, it may only have dozens of megabytes, and when it is large, it may have hundreds of megabytes, this irregular change is confusing for many people. Actually, pagefile. sys is a virtual memory in Windows. Its role is similar to that in physical memory, but it exists as a "backup force" of physical memory. That is to say, it only works when the physical memory is insufficient.

The computer has a great role in the computer. All running programs in the computer need to be executed through the memory. If the total amount of memory allocated by the executed program exceeds the memory size, the memory will be exhausted. To solve this problem, the virtual memory technology is used in Windows, that is, some hard disk space is used as the memory. When the memory is used up, the computer will automatically call the hard disk to act as the memory, to ease memory shortage.

Several possibilities of "insufficient Virtual Memory"

1. Virus Infection

Some viruses occupy a large amount of memory space during attack, leading to insufficient memory in the system. Go to antivirus, upgrade the virus database, and take anti-virus measures!

2. Improper virtual memory settings

Improper virtual memory settings may also cause insufficient memory. Generally, the virtual memory size is twice the physical memory size. If it is set too small, it will affect the normal operation of the system program. Re-adjust the virtual memory size. Take WinXP as an example. Right-click "my computer" and select "properties". On the "advanced" tab, click "set" in the "performance" box, switch to the "advanced" tab, click "change" in the "virtual memory" box, and then reset the virtual memory size. Then, restart the system.

3. Insufficient system space

The virtual memory file is in the system disk by default. For example, the virtual memory file name of WinXP is "pagefile. sys ". If the remaining space on the system disk is too small, the virtual memory is insufficient and the memory is insufficient. The system disk must retain at least MB of space. Of course, this value depends on your actual needs. Users should try not to install various applications on the system disk to ensure that there is sufficient space for virtual memory files, and it is best to place the virtual memory files in non-system disks.

4. Incorrect SYSTEM user permission settings

When an NT-based Windows SYSTEM is started, the SYSTEM user creates a virtual memory file for the SYSTEM. Some users use the NTFS file SYSTEM for SYSTEM security, but cancel the SYSTEM user's "write" and "modify" permissions on the SYSTEM disk, so that they cannot create virtual memory files for the SYSTEM, when running a large program, the memory is insufficient. The problem is well solved. You only need to re-grant the SYSTEM user the "write" and "modify" permissions, but this is only for users who use the NTFS file SYSTEM.