[1] With virtual machine software, you can simulate two or more virtual machines on a physical computer, and these virtual machines work in exactly the same way as real computers, for example, you can install the operating system, install applications, access network resources and so on. To you, it is just an application running on your physical computer, but to the application running on the virtual machine, it is a real computer. Therefore, when you evaluate the software in the virtual machine, the system may also crash; But it is only the operating system on the virtual machine that crashes, not the operating system on the physical computer. With the "undo" function of the virtual machine, the virtual machine can be immediately restored to the state before installing the software.

VMware

Before getting into the details, there are several concepts to explain:

1.VM (virtual machine)-A virtual machine refers to a virtual computer simulated by Vmware, that is, a logical computer.

2.HOST- refers to the physical computer, and Host'sOS refers to the operating system running on the host.

3. Guest operating system-refers to the operating system running on the virtual machine. For example, if Vmware is installed on a computer with WindowsNT installed, then HOST refers to a computer with WindowsNT installed, and the sOS of its host is WindowsNT. Linux runs on a VM, so Linux is a GuestOS.

trait

1. You can run multiple operating systems on the same PC at the same time, and each OS has its own independent virtual machine, just like an independent PC on the network.

2. Running two virtual machines at the same time on WindowsNT/2000 can talk to each other or the virtual machine in full screen mode, but at this time the other virtual machine is running in the background.

3. Install another distribution of the same operating system on the virtual machine without repartitioning the hard disk.

4. Virtual machines can share files, applications and network resources.

5. You can run C/S applications or use all the resources of another virtual machine on the same computer.

With Vmware, you can run various distributions of Linux, Dos, Windows and Unix at the same time, and even install multiple distributions of Linux and multiple versions of Windows on the same computer. After installing Vmware under WindowsNT, the author installed RedHatLinux on the VM, successfully ran Xwindow, and also installed Windows98 under the virtual machine. This is unbelievable! However, all this happened with the help of Vmware!

At present, Vmware's support for virtual hard disk capacity is still limited, up to 2GB. In addition, once the size of the virtual hard disk is determined, users are not allowed to change it in the future. The virtual hard disk is actually a file under WindowsNT, but for the GuestOS, it will always be regarded as an IDE hard disk. At present, there are no concepts of SCSI and RAID in virtual machines.

But you don't have to worry. Although virtual machines do not support SCSI disks, virtual disks can be built on any type of hard disk, including IDE, SCSI and even RAID arrays. The file systems on these disks can be FAT 16, FAT32, NTFS, etc. In addition, virtual disks can also be built on removable disks or network file servers. If the user wants, it can also be placed on a divided partition.

On the window of Vmware, several buttons are simulated, which represent turning on the virtual machine power supply, turning off the virtual machine power supply, reset key and so on. These keys function just like real keys. If your GuestOS is Linux, and you didn't shut down the Linux system through the halt command or reboot command. Then, the next time you start Linux, Linux will automatically check and repair the file system. Because it thought the last shutdown was a real power outage.

VMware enables you to run two or more Windows, DOS and LINUX systems on a single machine at the same time. Compared with the "multi-boot" system, VMWare adopts a completely different concept. Multi-boot system can only run one system at a time, and the machine needs to be restarted when the system is switched. VMWare is really running at the same time, and multiple operating systems switch on the platform of the main system, just like standard Windows applications. In addition, you can virtually partition and configure each operating system without affecting the data of the real hard disk. You can even connect several virtual machines into a LAN through a network card, which is extremely convenient. The performance of the operating system installed on VMware is much lower than that of the system directly installed on the hard disk, so it is more suitable for learning and testing. We can run WindowsNT, Linux, Windows9x and FreeBSD on the same PC at the same time, and we can immediately switch to Win9x to run Word while using Linux. If you want to use Linux, just click on it and go back to Linux. It's like having two computers working at the same time. The tool is: virtual computing platform-VMware.

virtual pc

VirtualPC was acquired by Microsoft, which didn't develop it at first. VirtualPC allows you to run multiple PC operating systems at the same time on a workstation. When you switch to a new operating system, it can provide a safe environment for you to run traditional applications to maintain compatibility. It can save reconfiguration time and make your support, development and training more effective.

OraclexVMVirtualBox

OracleVMVirtualBox is a software produced by sunMicrosystems (Sun was acquired by Oracle Bone Inscriptions in 20 10), which was originally developed by German innotek Company. On February 12, 2008, SunMicrosystems announced that it would acquire German Innotek Software Company by purchasing shares. The new version is no longer called InnotekVirtualBox, but called SunxVMVirtualBox. 2010 65438+1October 2 1, the EU finally agreed to Oracle Bone Inscriptions's acquisition of Sun, and VirtualBox was renamed OracleVMVirtualBox again. VirtualBox is open source software. At present, the operating systems supported by VirtualBox3.2.0 are Debian, Fedora, Linux, MacOS(Intel), Mandriva, OpenSolaris, PCLiunxOS, RedHat, SUSELinux, Solaris 10, Ubuntu, Windows, Xandros, openSUSE and so on. The client operating systems supported by OracleVMVirtualBox include all versions of Windows, Linux2.2, 2.4 and 2.6 kernels, Solarisx86, OS/2, OpenBSD, Netware, FreeBSD and DOS from 3. 1 to Vista. From June 5438 to October 2007 10, InnoTek released VirtualBox with GNUGeneralPublicLicense(GPL), and provided the binary version and open source version of the code. The latest version is VirtualBox4.2.6.