The server operating system generally refers to the system installed in theMainframeOperating system on, such as Web server, application server anddatabase serverEtc., which is the infrastructure platform of enterprise IT systemapplicationOne of the three types of operating systems (the other two areDesktop operating systemandEmbedded operating system）。At the same time, the server operating system can also be installed on a personal computer.Compared with personal versionoperating systemIn a specific network, the server operating system should undertake additional managementto configure, stability, security and other functions, located in the heart of each network.
The server operating system can directly control and manage the computer hardware and software.Any computer can't run without the operating system, so can the server.The server operating system is mainly divided into four schools: Windows ServerNetware、Unix、Linux。[1]
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Windows Server
Important versions: Windows NT Server 4.0, Windows 2000 Server, Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012. Windows Server operating system is applied in combination withNET development environment forMicrosoftEnterprise users provide a good application framework.
Netware
In some specific industries and institutions, NetWare has excellentBatch processingFunction and safe and stable system performance also have a large living space.The commonly used versions of NetWare are Novell 3.11, 3.12, 4.10, 5.0, and other Chinese and English versions.
Unix
Unix server operating system is jointly launched by AT&T Company and SCO Company, which mainly supports large file system services, data services and other applications.There are mainly SCO SVRBSD Unix、SUN Solaris、IBM-AIX、HP-U、FreeBSDX 。
Linux
Although the Linux operating system is similar to the UNIX operating system, it is not a variant of the UNIX operating system.Torvald imitated UNIX from the beginning of writing kernel code. Almost all UNIX tools and shells can run on LINUX.[2]
Operating System History
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Before 1980s
Part IcomputerThere is no operating system.But in 1947 he invented the transistor, andMaurice Wilkes (Maurice Vincent Wilkes)MicroprogramThe computer is no longer a mechanical device, but an electronic product.systemmanagement toolAnd the program to simplify the hardware operation process soon appeared, and became the foundation of the operating system.
By the early 1960s, commercial computer manufacturers had built batch processing systems that could build, schedule, and serialize jobs.At this time, the manufacturer creates different operating systems for each computer of different models, so programs written for one computer cannot be transplanted to other computers for execution, even for computers of the same model.
By 1964,IBMLaunched a series of mainframe computers IBM System/360 with different uses and prices.And they all share the code nameOS/360The operating system of (rather than the customized operating system for each product).Making a single operating system applicable to the whole series of products is the key to the success of System/360. In fact, IBM large-scale systems are the descendants of this system;Applications written for System/360 can still be executed on modern IBM machines!
OS/360 also includes another advantage: the availability of permanent storage devices hard disk drives（IBMIt is called DASD (Direct access storage device).Another key is the establishment of the concept of time sharing: properly allocate the precious time resources of mainframe computers to all users.Time sharing also gives users the feeling of monopolizing the whole machine;andMulticsOfTime-sharing systemIt is the most successful one to practice this concept in many new operating systems at this time.
In 1963, Strange Company andBell LaboratoriesCooperate toPL/IThe Multics language was the source of inspiration for the establishment of many operating systems in the 1970sAT&TDennis Ritchie of Bell Labs andKen ThompsonEstablishedUnixIn order to practice the platform portability, this operating system was developed byC languagerewrite;Another small computer operating system widely used in the market isVMS。[2]
1980s
The first generation of microcomputers did not have the need or ability to install operating systems, unlike large or small computers;They only need the most basic operating system, which is usually based onROMRead, this kind of program is called monitor program（Monitor）。
In the 1980s,Home computerStart to popularize.Usually, the computer at this time has an 8-bit processor plus 64KB of memory, screenkeyboardAnd a bass horn.The most famous suite computer in the early 1980s wasmicroprocessor6510（6502chipSpecial Edition).This computer does not have an operating system, but uses 8KB read-only memory BIOS to initialize colorscreen, keyboard and floppy drive andprinter。It can use 8KB read-only memoryBASIC languageTo directly operate the BIOS and write programs based on it, most of them are games.The interpreter of BASIC language is barely the operating system of this computer.
The most famous early disk boot operating system isCP/M, it supports many early microcomputers, and its functions areMS-DOSMassive plagiarism.
The earliest IBM PCs were similar in architecture to C64.Of course, they also useBIOSTo initialize and abstract hardware operations, even a BASIC interpreter is attached!But the reason that its BASIC is superior to other companies' products is that it is portable and compatible with any machine that conforms to IBM PC architecture.Such a PC can be addressed with the Intel-8088 processor (16 bit register), and can have up to 1MB of memory, but initially only 640KB.The floppy disk drive has replaced the tape drive in the past, becoming a new generation of storage equipment, and can read and write on its 512KB space.To support further file read/write concepts,Disk Operating System（Disk Operating System，DOS）So it was born.This operating system can merge any number of sectors, so it can place any number and size of files on a disk.Files are distinguished by file names.IBMThey didn't care much about the DOS on it, so they bought it from external companiesoperating system。
In 1980, Microsoft Corporation obtained a contract with IBM, and acquired an operating system produced by a company, which was modified and produced in the name of MS-DOS. This operating system can directly allow programs to operate BIOS and file system.Arrived at Intel-80286processorOnly in the era of "," began to implement basic storage equipment protection measures.MS-DOSThe architecture of can not fully meet all requirements, because it can only run at most one program at a time (if you want to run programs at the same time, you can only use the TSR method to skip the OS and let the program handle the multi task part by itself), and there is no memory protection measures.The support for drivers is not complete enough, which leads to situations such as the sound effect device must be set by the program itself. There are many cases of incompatibility.Many applications therefore skip MS-DOS services and access hardware devices directly to achieve better performance.Nevertheless, MS-DOS has become the most commonly used operating system on IBM PCsPC-DOS）。The success of MS-DOS has made Microsoft one of the most profitable companies on earth.
Another operating system exception that rose in the 1980s isMac OS, this operating system is closely related toMacintoshBundled together.At this time, Dominik Hagen, an employee of Xerox Palo Alto Research Center, visitedApple ComputerOfSteve JobsAnd showed him the graphical user interface developed by Xerox at this time.Apple Computer was so amazing that it planned to buy this technology from Xerox, but because the Palo Alto Research Center was not a commercial unit but a research unit, Xerox rejected the deal.After that, Apple agreed that the future of personal computers must belong to the graphical user interface, so it also began to develop its own graphical operating system.Nowadays, many graphical interface technologies and rules that we consider as basic requirements are based on Apple computer (such as pull-down menu, desktopIcon, drag and drop operation, double click, etc.).But correctly, the graphical user interface was created by Xerox.[2]
1990s
Apple computers,AppleThe first generation of computer products.Continuing the competition in the 1980s, many operating systems emerged in the 1990s that will have a profound impact on the future PC market.Due to the increasingly complex graphical user interface and the increasingly complex and huge capacity of the operating system, a strong and flexible operating system has become an urgent need.This is an era when many packaged PC operating systems compete with each other.
Apple Computer, which rose in the market in the last decade, decided to redesign its operating system because of the poor design of the old system, which made its subsequent development ineffective.After many failed projects, Apple released its new operating system, MacOS, in 1997testThe official version launched later has achieved great success.Let the former frustrated leave AppleSteve JobsThe scenery reappears.
In addition to commercial mainstream operating systems, in the open source world since the 1980s,BSDThe system has also developed for a long time, but in the 1990s, due to the legal dispute with AT&TOpen SourceOperating system——Linuxrise.LinuxkernelIs a standardPOSIXThe kernel is a branch of the Unix family.Linux is compatible with BSD familyGNUThe applications planned to be developed, but due to the use of licenses and historical factors, Linux has achieved a considerable market share of open source operating systems, while BSD is much smaller.
Compared toMS-DOSIn addition to its impressive portability (compared with Linux, MS-DOS can only run on Intel CPUs), Linux is also a time-sharing multi process kernel and has good memory space management (ordinary processes cannot access the memory in the kernel area).Processes that want to access any memory space other than their own can only usesystem callTo achieve.commonlyprocessIt is in the user mode, and the system call will be switched to the kernel mode. All special instructions can only be executed in the kernel mode. This measure allows the kernel to perfectly manage the internal and external devices of the system, and reject requests from unauthorized processes.Therefore, theoretically, any error in the execution of an application program cannot crash the system.
On the other hand, Microsoft's response to the call for a stronger operating system isWindows NTIt was launched in 1993.
Since 1983, Microsoft has wanted toMS-DOSBuild a graphical operating system application calledWindows(Some people say that Bill Gates was killed by AppleLisaStimulated by the listing of computers).
in limineWindowsIt is not an operating system, but an application program. Its background is a pure MS-DOS system, because the BIOS design and MS-DOS architecture at that time were not very good.
In the early 1990s, the cooperation between Microsoft and IBM broke down, and MicrosoftOS/2(In the early stage, it was a command line mode, but later it became a very successful graphical operating system.) It was released on July 27, 1993Windows NT 3.1, an OS/2 based graphical operating system.
Until then, the Windows system was still based on MS-DOS, so consumers expected Microsoft to launch theWindows 2000Because it is the first graphical operating system that breaks away from the MS-DOS foundation.
The architecture of the Windows NT system is that there is a hardware abstraction layer (HAL) directly contacted by the microkernel on top of the hardware layer, and different drivers are mounted on the kernel and executed in the form of modules.Therefore, microkernel can use input/output, file system, network, information security mechanism andvirtual memoryAnd other functions.andsystem service Layer provides a function call library of all unified specifications, which can unify the implementation methods of all subsystems.For example, althoughPOSIXThe name and calling method of the same service are quite different from those of OS/2. They can also be implemented on the system service layer without hindrance.The subsystems above the system service layer are all consumer models, so the execution of consumer programs can be avoidedillegalget some action.
The DOS subsystem executes each DOS program as a process, and uses individual independent MS-DOSvirtual machineThe server hosts its running environment.The other is the Windows 3.1 NT simulation system, which actually executes Win16 programs under the Win32 subsystem.Therefore, the ability to safely control the old programs written for MS-DOS and early Windows systems has been achieved.However, this architecture is only implemented on Intel 80386 processors and subsequent models.In addition, some programs that can directly read hardware, such as most Win16 games, cannot be applied to this system, so many early games cannot be executed on Windows NT.
Windows NT has versions 3.1.3.5.3.51 and 4.0.
Windows 2000 is an improvement series of Windows NT (actually Windows NT 5.0)Windows XP(Windows NT 5.1) andWindows Server 2003（Windows NT 5.2）、Windows Vista(Windows NT 6.0) and Windows 7 (Windows NT 6.1) are also based on the Windows NT architecture.
However, the number ofEmbedded deviceThe market also promotes the growth of embedded operating systems.
mainframeWith embedded systems, many kinds of operating systems are used.Many mainframes begin to support Java and Linux to share resources of other platforms.A hundred schools of thought contend for embedded systems, from Berkeley Tiny OS for Sensor Networks to operableMicrosoft OfficeOfWindows CEBoth.[2]
twenty-first century
Modern operating systems usually have a graphical user interface for the drawing equipment used（GUI）, and add input devices different from the keyboard, such as mouse or touch panel.Old OS or performance oriented servers usually do not have such a friendly interface. Instead, they use the command line interface (CLI) and keyboard as input devices.The above two interfaces are actually so-called shells, whose function is to accept and process user instructions (for example, press a button, or type instructions on the command prompt column).
The choice of the operating system to install usually has a lot to do with its hardware architecture. Only Linux and BSD can run on almost all hardware architectures, while Windows NT is only migrated to DEC Alpha and MIPS Magnum.In the early 1990s, the choice of personal computers has been limited to the Windows family, the Unix like family and Linux, and Linux and Mac OS X are the most important alternative choices until today.
Mainframe and embedded systems use a variety of operating systems.Linux, UNIX, andWindowsServer occupies most of the market share.In terms of supercomputers, Linux has replaced Unix as the largest operating system. As of June 2012, the ranking of the world's top 500 supercomputers based onLinuxThe supercomputer accounted for 462 seats, up to 92%.With the development of smart phones, Android and iOS have become the two most popular mobile phone operating systems.[1]
In 2012, the globalIntelligent mobile phoneThe change of operating system market share is relatively stable.The smartphone operating system market has been controlled by several mobile phone manufacturers, and Android's monopoly position is mainly due to Samsung's great success in smart phones worldwide.In the third quarter of 2012, Android's market share reached 74.8%, compared with 57.4% in 2011.In the first quarter of 2013, its market share continued to increase, reaching 75%.Although Android takes the lead, AppleiOSUsers spend more time on applications than Android.Although the number of Android was once close to that of Apple in this respect, the number of Apple will continue to grow after the release of devices such as the iPad 3.After the release of version 8.1, the market share of Windows Phone system has steadily increased, the application ecosystem is improving, and many necessary applications are constantly updated, but the speed is still slightly slow.Microsoft acquired Nokia, developed many OEM manufacturers, and continuously released new models to try to reverse the adverse situation of WP, with little success.[2]
