Server

Server refers to the network environment for other clients (such as PCS, smart phones, ATM terminals and even large equipment such as train system) to provide a certain service dedicated computer, it is faster than ordinary computers, higher load, more expensive. The server has high-speed CPU computing power, long-term reliable operation, strong I/O external data throughput capacity and better scalability.

What is a server?

Server is a kind of computer, the English name of the server is "server", refers to the network environment for the client (such as PC, smart phone, ATM and other terminals and even train system and other large equipment) to provide some kind of service computer. Server A computer installed with a network operating system (such as Windows 2000 Server, Linux, Unix, etc.) and various server application system software (such as Web services, E-mail services).

Compared with ordinary computers, the server has higher requirements in terms of stability, security, performance, etc., so the CPU, chipset, memory, disk system, network and other hardware are different from ordinary computers.

Servers provide computing or application services to other clients in the network, such as PCS, smartphones, ATMs and other terminals, and even large devices such as train systems. The server has high-speed CPU computing power, long-term reliable operation, strong I/O external data throughput capacity and better scalability.

The server is the node of the network, storing and processing 80% of the data and information on the network, and plays an important role in the network. They are high performance computers that provide various services for client computers, and their high performance mainly includes high speed computing power, long-term reliable operation, strong external data throughput capacity and so on. The composition of the server is similar to that of an ordinary computer, with processors, hard disks, memory, system bus, etc., but because it is specially developed for specific network applications, the server and the computer differ greatly in terms of processing power, stability, reliability, security, scalability, manageability, etc. The main servers are network servers (DNS, DHCP), print servers, terminal servers, disk servers, mail servers, file servers, etc.

Role of server

1, as a node of the network, the server stores and processes 80% of the data and information on the network, so it is also known as the soul of the network.

2, make an image metaphor: the server is like the post office switch, and the computer, notebook, PDA, mobile phone and other fixed or mobile network terminals, just like the telephone scattered in the family, various office places, public places and so on.

3, our daily life and work with the outside world in the telephone exchange, communication, must go through the exchange, in order to reach the target phone; Similarly, the network terminal equipment such as home, enterprise microcomputer Internet access, access to information, communication with the outside world, entertainment, etc., must also go through the server, so it can be said that the server in the "organization" and "leadership" of these devices.

4, it is a kind of network for the client computer to provide a variety of services high availability computer, it under the control of the network operating system, will be connected to the hard disk, tape, printer, Modem and a variety of special communication equipment to the network of the customer site sharing, but also for the network users to provide centralized computing, information publication and data management services.

5, its high performance is mainly reflected in high-speed computing power, long-term reliable operation, strong external data throughput capacity and so on.

The server is powered on for 24 hours

1, because people visit the website during the day and night, so it should be turned on. If it is an internationally renowned website, it is even more, almost can not stop, but stop the service, the consequences are unimaginable.

2, the general server requires 24 hours of power on for many years, and occasionally needs to shut down for maintenance.

Server operating system

There is no server hardware, but also a system, the current mainly divided into Microsoft development of windows server system (win2003, win2008, win2012, win2016, win2019, win2022),Linux system, unix server

Windows Server

Major versions Windows NT Server 4.0, Windows 2000 Server, Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, and Windows Server 2008 R2, Windows Server 2012, windows server 2016, windows server 2019, windows server? In 2022. Windows server operating system pie application, combined. NET development environment provides a good application framework for Microsoft enterprise users.

Netware

In some specific industries and institutions, NetWare's excellent batch processing functions and secure and stable system performance also have a lot of room to live. NetWare is commonly used in Novell 3.11, 3.12, 4.10, 5.0 and other Chinese and English versions.

Unix

Unix server operating system by AT&T and SCO jointly launched, mainly to support large file system services, data services and other applications. The main ones circulating in the market are SCO SVR, BSD Unix, SUN Solaris, IBM-AIX, HP-U, FreeBSDX.

Linux

The Linux operating system is similar to the UNIX operating system, but it is not a variant of the UNIX operating system. Torvald began writing kernel code modeled after UNIX, and almost all UNIX tools and shells can run on LINUX.

This is a new type of network operating system, its biggest feature is the open source code, you can get many applications for free. There is also a Chinese version of Linux, and Linux servers have many different systems, such as Ubuntu, Debian, CentOS, Red Hat, openSUSE, Fedora, Gentoo, etc. In the country has been fully affirmed by users, mainly reflected in its security and stability, it has many similarities with Unix. However, at present, this type of operating system is still mainly used in medium and high-end servers.

Linux systems are free software similar to UNIX systems, mainly used on computers based on Intel x86 cpus. Because the Linux system has all the functions of the UNIX system, and is a free free software, users do not need to pay any fees to get its source code, and can freely modify and supplement, so it has been supported by the majority of computer enthusiasts. After the majority of computer enthusiasts continue to modify and supplement, the Linux system has gradually become a powerful, stable and reliable operating system.

Server location

The server should be placed in the computer room, because the server needs to be on for 24 hours all day, 365 days of uninterrupted work, heat dissipation is more important, so the server needs to be placed in a relatively stable and suitable environment, constant temperature, constant humidity, dust, power supply and so on. In the equipment room, use air conditioners to ensure constant temperature, humidity, dust and power supply.

Server category:

According to the architecture, there are two main types of servers:

(1) Non-x86 servers:

1) Includes mainframes, minicomputers, and UNIX servers, which are servers that use RISC (Reduced Instruction set) or EPIC (Parallel Instruction Code) processors and are primarily powered by UNIX and other specialized operating systems.

2. Reduced instruction set processors mainly include IBM's POWER and PowerPC processors, SUN's SPARC processor developed in cooperation with Fujitsu, and EPIC's Itanium processor developed by Intel.

3, This kind of server is expensive, the system is closed, but good stability, strong performance, mainly used in the core system of large enterprises such as finance and telecommunications.

(2) x86 server:

1, also known as CISC (complex instruction set) architecture server, that is, usually referred to as the PC server, it is based on the PC architecture, the use of Intel or other compatible x86 instruction set processor chips and Windows operating system server.

2, cheap price, good compatibility, poor stability, security is not too high, mainly used in small and medium-sized enterprises and non-critical business.

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Precautions for the server room

1, the stable supply of power is a necessary condition for the normal operation of the server, but also the basis for the server to serve the enterprise. Therefore, when we arrange the power system of the computer room, we need to consider the conventional power situation of the normal operation of the server, and also need to take into account the response measures when the emergency situation. For example, in order to ensure the security of server data, a large-scale UPS distribution cabinet with high specifications is required to ensure that the server can continue to run for a period of time after a power failure. For example, the power line of the server room and other facilities are separated from the power supply is also a measure of server power stability.

2, the stable operation of the server also needs to control the temperature. If there is no temperature control equipment, the CPU temperature of most servers is generally above 60 degrees during operation, the temperature will be higher in the hot summer, long-term in a high temperature environment will affect the performance of the server, so the server room is generally required to configure precision air conditioning, the use of air conditioning to control the ambient temperature of the room at about 18 to 25 degrees. Prevent the server from continuously running at high temperatures.

3, humidity on the server is also a great impact, such as humidity is too low, it is easy to produce static electricity, accidentally lead to capacitor or other chips are broken down. If the ambient humidity is too high, there may be condensation on the circuit, resulting in reduced circuit insulation or even short circuit. Long-term humid environment may produce mildew, damaging the circuit system of the server. Generally, the humidity of the server room must be between 45% and 55%. If possible, it is recommended to raise the cabinet and lay moisture-proof materials under the floor.

4. Dust is the killer of all electronic devices. If a large amount of dust covers the circuit of the server motherboard, it is easy to cause short circuit; Attached to the cooling fan, it will also increase the load of the cooling fan and affect the heat dissipation effect. Therefore, take good dust prevention measures in the equipment room of the server. For example, wear disposable dust proof shoes or prepare special slippers for the equipment room when entering the equipment room. At the same time, the server needs to be cleaned regularly. Do not open the doors and Windows of the server room for a long time.

5, the room also needs to do a good job of fire and lightning protection measures. Although the equipment room requires the use of insulating refractory materials, but also must do a good job of protective measures, such as the purchase of high standard strip, non-smoking in the equipment room, equipped with fire equipment, if possible, can install an independent smoke sensor. Servers and other electronic equipment are very sensitive to the current pulse, so in the layout of the server room must take into account lightning protection and lightning protection measures, the instantaneous large current pulse in the circuit may breakdown the server.

6. Other matters that need attention. Do not expose the server to direct sunlight for a long time, because sunlight will cause the surface temperature of the server to rise. Do not place too many servers in one cabinet because the bearing capacity of the cabinet is limited. When arranging the server room, it is necessary to make long-term planning, and the discharge of the cabinet and the location of the distribution frame need to be planned in advance, so as to make better use of the space and facilitate management.

The server has a proper maintenance, in order to effectively extend the service life of the server, improve work efficiency and performance, after all, the server is generally 24 hours a year to serve us.

Server characteristics

1. Scalability

Servers must be "scalable" because enterprise networks cannot remain static for long, especially in today's information age. If the server does not have a certain scalability, when the number of users is not competent, a value of tens of thousands, or even hundreds of thousands of servers will be eliminated in a short time, which is no enterprise can afford. In order to maintain scalability, it is usually necessary to have a certain amount of expandable space and redundancy on the server (such as disk array racks, PCI, and memory slot bits).

2. Ease of use

The function of the server is much more complex than that of the PC, not only referring to its hardware configuration, but also referring to its software system configuration. The server has so much to accomplish that it is impossible to imagine without comprehensive software support. However, a large number of software systems may cause the performance of the server to decline, and managers can not effectively manipulate. Therefore, many server manufacturers in the design of the server, in addition to the availability of the server, stability and other aspects to fully consider, but also must be in the ease of use of the server under the full effort. The ease of use of the server is mainly reflected in whether the server is easy to operate, whether the user navigation system is perfect, whether the chassis design is humanized, whether there is a key recovery function, whether there is an operating system backup, and whether there is enough training support.

3. Availability

For a server, a very important aspect is its "availability", that is, the selected server can meet the requirements of long-term stable work, and can not often go wrong. In fact, it is equivalent to the Reliability proposed by Sun. [3] Because the server is facing the entire network of users, rather than a single user, in large and medium-sized enterprises, the server is usually required to be uninterrupted. In some special application areas, even if there is no user use, some servers have to work uninterrupted, because it must continue to provide users with connection services, whether it is at work, or off work, whether it is working days, or rest, holidays. This is the fundamental reason why the server must have extremely high stability. In general, specialized servers are 7X24 hours uninterrupted work, especially like some large web servers, such as servers used by large companies, web servers, and public service iqdeWEB servers. For these servers, perhaps the number of real work boot only once, that is, it has just bought back the full installation and configuration of the formal use of the time, since then, it continues to work uninterrupted until completely scrapped. If things go wrong at every turn, it is impossible for the network to maintain normal operation for long. In order to ensure that the server has a high "availability", in addition to requiring the quality of each component, you can also take the necessary technical and configuration measures, such as hardware redundancy, online diagnosis, etc.

4. Easy management

Among the main features of the server, there is another important feature, which is the "manageability" of the server. Although we say that the server needs to work continuously without interruption, but no matter how good the product can fail, people often say that is: not do not know it may break, but do not know when it will break. Although the server has sufficient protection in terms of stability, it should also have necessary measures to avoid errors, timely detection of problems, and failure can be maintained in a timely manner. This not only reduces the chance of server errors, but also greatly improves the efficiency of server maintenance. In fact, it is the Serviceability proposed by Sun. The easy management of the server is also reflected in whether the server has an intelligent management system, whether there is an automatic alarm function, whether there is an independent management system with the system, and whether there is an LCD monitor. Only in this way, administrators can easily manage and work efficiently.