What is the difference between a server and a computer. The difference between a server and a regular computer. How does a server differ from a regular computer?

Usually the word “server” scares users. It seems like some kind of colossus, like a computer from the middle of the last century, occupying the halls and requiring servicing by crowds of concentrated programmers. And she seems to be somewhere far away, and is not connected with ordinary human life, and solves terribly specific problems. In fact, a server computer has much more in common with the PCs we are used to, especially if the server is low-power and serves not a giant corporation, but a local area at the entrance level or a small office.

Definition

Server, or server computer - a computer that meets certain tasks and conditions, processes requests from other computers included in the same network, and is equipped with appropriate software.

Under regular computer understand a home or office PC with standard characteristics, regardless of participation in the local network.

Comparison

The difference between a server and a regular computer comes from the tasks of both. The server, as serving all network participants, must be more productive in order to process requests as quickly as possible. The wider the network, the more powerful the server. To organize a small network, no hardware specifications are needed; server software that manages multiple connections and provides remote access to resources is sufficient. For more serious tasks, the configuration must be appropriate: server multiprocessor motherboards, large RAM, many drives, all of this must be enclosed in a well-ventilated case.

A server, unlike a home PC, does not need graphics power; most often it does not have a video card, and the monitor is connected to an integrated one. The server can work as long as the owners need, but most often uninterruptedly on a 24/7 schedule, so the cooling system and power supply system must be resistant to overloads, not to mention the electronics of the most important element - the drives. In addition, special hard drives are installed in server stations; manufacturers often mark them. They are distinguished by a huge number of revolutions - 10,000, and are much more expensive than those installed in PCs. In general, all components for a server are more expensive, and its maintenance is not cheap, given that the energy-intensive system does not turn off for a long time.

In addition, the server requires careful attention to the creation of backup copies, and backups on it are a constant matter, even if it serves not a work network, but a home network. To do this, in addition to software, they use the ability to connect drives in RAID.

Conclusions website

1. The server serves many connected computers.
2. The server demonstrates higher performance.
3. The server requires special components.
4. The server ignores the graphics capabilities of the systems.
5. A server is an expensive pleasure.

A server is a powerful computer that serves other computers on a local network. ComputerBild will tell you how a server differs from a regular PC.

In any large computer network, there is a constant need to share resources between several computers, be it a shared Internet connection, access to multimedia files, or printing documents on one printer. The computer that provides these resources to other machines is called a server. The nature of these resources determines the type of server. The file server stores data, the print server receives documents and sends them to a printer connected to it, connecting to a proxy server to access the Internet, computers share an access channel... These and other functions can be performed by different machines or by one computer.

The difference between a server and a regular PC

Servers that are used in home local systems and small businesses, as a rule, differ from ordinary PCs only in the software installed on them. Another thing is the servers of large organizations. The load on their computing resources and storage devices is very high. These machines must accommodate large volumes of documents and provide high speed access to them. Also, no less important, the server requires uninterrupted operation and high fault tolerance. Therefore, large servers generally consist of more complex and high-performance hardware than conventional PCs. At the same time, some hardware components, the functions of which are secondary to the server, turn out to be weaker than their counterparts in a home PC. These are the components that distinguish servers from simple computers.

Powerful processors. Servers use dedicated CPUs, such as Intel's Xeon or AMD's Opteron. More exotic “stones” are also used, for example Intel Itanium. Entry-level servers, like simple PCs, have one processor, larger ones have from two to eight. The most powerful servers are clusters of hundreds of processors with accompanying hardware - motherboards, drives, etc.

Large amount of RAM. If a home PC needs a couple of gigabytes of RAM for full operation, or 4 in worst cases, then a powerful server requires 8-16 GB or even more. Server memory modules themselves, as a rule, have an error correction function - ECC (Error Correction Code). Thanks to this, errors in writing and reading data caused by a malfunction of electronics or a defect in memory chips will not lead to interruptions in the operation of the “software” or freezing of the system, as would happen with a regular computer.

High-capacity storage devices. In most servers, data is stored on fast and capacious hard drives, which are combined into RAID arrays. Since the server simultaneously requires high speed and fault tolerance, array formats combine data division across several hard drives with duplication of information on other “screws”. It is often possible to disconnect and connect drives “hot” - i.e. without interrupting the system.

Broadband network connection. If a server is used to share Internet access between dozens of computers, then it connects to the global Internet using a “thick” high-bandwidth channel. For this, fiber optic lines or radio channels are used. Client computers connect to the server using standard Ethernet or Wi-Fi technologies.

The hardware that performs secondary service functions on servers also differs from the peripherals of client PCs.

Frame. The server's objectives determine its design. Low-end servers look like regular PCs, only enlarged to accommodate a larger motherboard and storage array. More powerful servers use rack cabinets as enclosures, and often they consist of several units (computers, routers, etc.) in separate enclosures. A very powerful server cluster can consist of several dozen such cabinets. A computer housed in a compact rack-mountable case is called a blade server.

Power unit. Entry-level servers are equipped with one or two power supplies. As the number of functional units of the server increases and their “appetites” increase, the number and power of power supplies increase. It is often possible to “hot” swap or connect an additional power supply.

Output devices. Since video and audio output is a client task, not a server task, servers either have no devices for this purpose at all (then the system is controlled remotely from the client PC) or are quite primitive.

The operating and hardware features of a powerful server also dictate the need for its specific maintenance.

Uninterrupted power supply. Industrial surge protectors and uninterruptible power supplies prevent data loss in the event of voltage dips in the electrical network, and also reduce the likelihood of damage to hardware and files due to sudden changes. In some cases, when uninterrupted operation is required in spite of everything, backup power generators are used.

Enhanced cooling. Most servers, like client PCs, are air cooled. The problem of heat dissipation increasing along with performance is solved with the help of enhanced ventilation of cases and rooms where servers are installed. Servers do not require enhanced cooling of individual components, so water cooling systems are not found in them

Specialized software. Operating systems adapted to server tasks are installed on servers, such as Windows Server 2003, special versions of Linux or Free BSD, or purely server operating systems, such as Solaris from Sun Microsys- tems. The main software used is server programs, such as Apache to support websites or Microsoft Exchange Server to receive and send email.

Server types

A server refers not only to a computer, but also to software that manages shared resources and access to them. Several server programs can run simultaneously on one computer. In everyday life, when talking, for example, about a “mail server”, they mean a combination of “hardware” and “software”. Depending on the functions that the software performs, there are several types of servers. All of them can be divided into two groups: servers, whose task is to store data and provide access to users, and servers that manage data transport on the network and support its operation. The first group includes the following types of servers.

File server. Its tasks include storing files and providing access to them on client PCs, for example via the FTP protocol. File server resources can either be open to all computers on the network, or protected by an identification system and access rights.

Multimedia servers are a type of file server. They are designed to store photos, music, movies and other multimedia content. It is not necessary to use a computer as such a server. You can buy a NAS device or even get by with a compact external hard drive that connects to the network via Ethernet or Wi-Fi.

The print server accepts print requests from computers on the local network and sends them to one or more printers connected to it.

Game servers. Computer game developers open special servers on which users can play with each other. 3D shooter and strategy servers were once the most popular, allowing only one match at a time or several at a time. It’s rare that a home or neighborhood “local area” can do without such a server. Nowadays, servers of various MMORPGs (Massive Multiplayer Online Role Playing Game) are more in demand, on which hundreds and thousands of people can play simultaneously (example: the games Lineage 2 and World of Warcraft).

Email servers. An email cannot be sent directly to the recipient - it first goes to the server where the sender's account is registered. That, in turn, sends a “parcel” to the recipient’s server, from which the latter picks up the message. Despite the fact that both receiving and sending letters is performed by the same server program, formally these functions are assigned to different servers with different addresses.

Instant messaging servers. Messenger programs - AIM, ICQ or MSN Messenger - work using a network of communication servers that operate on the same general principle as mail servers.

Web servers. These servers provide access to web pages and related resources, such as pictures. Websites with high traffic or advanced functionality are hosted on several servers at once.

Data servers store various types of materials necessary for the functioning of servers for other purposes. For example, some text, graphics and style elements of a website may be located on a separate data server. When the user opens the start page of the site, the web server sends a request to the data server to obtain the necessary materials. The database server searches for the requested data and sends it to the web server. It, in turn, generates a web page and sends it to the client computer.

The list of servers that manage traffic transport includes the following types.

DHCP servers. Dynamic Host Configuration Protocol provides automatic distribution of IP addresses between computers on the network. This technology is widely used in local networks with shared Internet access.

DNS servers. The function of a DNS server is to resolve domain names of servers into IP addresses. Data transfer on networks is carried out using IP addresses; a site with an unchanged domain name can “move” from one server to another more than once, changing its IP address. Therefore, the tables of correspondence between IP addresses and domain names in the DNS (Domain Name System) system are regularly updated, and the servers synchronize them with each other.

Proxy servers act as intermediaries when transferring data over the network - from computer to computer. They are used either to organize shared access to the Internet, when control and filtering of traffic is required, or to hide the IP address of a PC from the “interlocutor” computer, because the latter, when communicating through a proxy server, will “see” only the proxy address.

Cache servers. So that every time a web page is opened, the client computer does not have to re-request all of its constituent data, intermediate storage devices are used - cache servers. If the page requested by the user has not changed since the last request, then it can be loaded not from the “native” storage, but from the depths of the cache server.

Client-server and Peer-to-Peer architectures

If the computer that provides resources is a server, then the computer that uses them is called a client. In addition, a client, like a server, is also a program for accessing resources (for example, an email client or an instant messaging program).

Most traditional Internet services are based on a client-server architecture. But recently, a fundamentally different network organization has become widespread.

In Peer-to-Peer (P2P) architecture, all computers have equal rights and each one stores a portion of the total amount of data. In this case, each machine acts simultaneously as both a client and a server. The most successful example of P2P implementation is file-sharing networks (eDon-key2000, Bit-Torrent). When you receive a file from such a network, you simultaneously download fragments of it from dozens of computers. Thanks to data distribution, peer-to-peer (aka peer-to-peer, decentralized) networks are characterized by high fault tolerance and speed.

In fairness, we must admit that most peer-to-peer networks cannot do without servers at all. For example, file-sharing networks use servers (trackers) to manage and account for traffic.

Home server

All modern operating systems have server capabilities. With their help, you can give users of other PCs access to data on the hard drive or to a printer connected to the computer, as well as “share” the Internet connection. In addition, a home server can be used for backup data storage or, by making it accessible via the Internet, work with documents on it from any PC connected to the global Internet.

“Raising” a home server for storing files and sharing access to the Internet is not as difficult as it might seem to an inexperienced user. To do this you will need the following components.

Computer. For a file or simple web server, a computer with a processor no weaker than a Pentium II or Athlon, 256 MB of RAM and a CD-ROM drive is sufficient. If you plan to run a game server on your computer (a very popular initiative in small local networks), you will need a more powerful machine.

As a first step, you can run a Linux server on it from a Live-CD. After playing around with it, you will decide whether you should move on to more serious activities. If you do decide to use your computer as a server permanently, then Linux will need to be installed on your hard drive. 10 GB of free space is enough for this. The rest of the space will remain for files and additional software (primarily server programs).

It's a good idea to use an old laptop as a server. With prolonged use, this will save on energy bills. In addition, the folded laptop takes up very little space. The only drawback of the laptop in this case is the limited capabilities for connecting storage devices.

Linux distribution. With a free version of Linux (Open SuSe, Ubuntu or Knoppix) you can create a server that has all the features you need for home use.

Most Linux distributions also have paid versions - for example, in the case of SuSe, it is called SuSe Enterprise Server. This version of Linux features additional technical support from the manufacturer and an expanded set of programs.

Network hard drives

/>

WLAN routers and network hard drives

Operating a home network rarely requires using a separate PC as a server. Depending on the amount of data it will store and the tasks it will perform, you can choose one of two cheaper options.

WLAN router plus external hard drive

Many wireless routers have a USB port that you can connect to an external hard drive. Any computer on the network will have access to the data stored on it.

Network hard drives

Network Attached Storage (NAS) is a compact and inexpensive (compared to a separate PC) server that performs only one function - data storage. Powerful NAS have a rich set of interfaces and the ability to remotely configure via a web interface (similar to routers). Simpler options for this solution are regular external hard drives with an Ethernet or Wi-Fi network interface.

It makes sense to install a server based on a full-fledged computer only if the functionality of the NAS is no longer sufficient: for example, you need to “raise” a small game server on your home network or a website. For these purposes, an old computer running Linux will suffice, although Windows can also be used.

Greetings, friends!

Today we will talk about serious “hardware”, designed more abruptly than a household computer.

Hardware and software server

Many of us have heard the buzzwords “server” and “file server” and the phrases “mail server”, “dedicated server”, etc.

In this article we will take a look at what is a server, how it works, and how it differs from a household or office computer.

The word server is derived from the English term to serve. Thus, the server is the "server".

It doesn't sound very nice, but it's clear what he does. Serves customer requests.

It can be serviced at the hardware (“hardware”) and software levels.

Therefore, the concept of server includes two - “hardware server” and “software server”.

Let us immediately point out the first difference between a server and a personal computer (PC). The user constantly works on a personal computer. And the server (hardware), in most cases, stands quietly in a separate room and works independently.

An ordinary user does not work behind it, the system administrator only sometimes sits down with him - for configuration or other service manipulations. It is necessarily included in the local network (otherwise how will it serve client requests?) Therefore, it can be accessed from any computer from this network (with appropriate settings, of course). A hardware server, unlike a PC, operates 24 hours a day, seven days a week.

Software server

A software server is a software package that serves client requests.

This ideology implies the presence two parts software package - server and client. The main part is the server part. It is located on the hardware server (physically on its hard drive).

This ideology is used by many programs, in particular accounting ones. The server stores the main part of the program and the user database. The user interacts with the main part through the client part located on his computer.

Several (or many) clients can work simultaneously in the main module. Therefore, the hardware must have the necessary computing power. Depending on the type of software server, the hardware may have different requirements.

Mail server is a program that works with mail. Of course, there is also its hardware part, where the letters are actually physically stored.

Any search engine also includes a mail service. Nowadays, getting yourself a mailbox (or even several) on a server is not a problem.

There is such a thing as a “file server”. This is a storage for many files, where many users are allowed access. There can be a lot of files, so the hardware must have large disk memory. The software part is undoubtedly very interesting, but our blog is about hardware, so let’s look in a little more detail at how the hardware server works.

Let us immediately note that the server can work for months without shutting down. Therefore he must have much more reliable Hardware. Increased reliability is ensured, in particular, by higher quality and more expensive components.

RAM

Used with ECC parity(Error Correction Code). The fact is that there is always some non-zero probability of an error in RAM.

It’s one thing when an error or failure occurs on the user’s computer when he is working with his own application (and not on the server). The cost of such a mistake is most often small.

It’s another matter when someone’s transaction worth a million dollars is “lost” on the server.

Errors on the server are also dealt with using hardware, using redundant data encoding. The information is supplied with additional (service) bits, which makes it possible to detect and correct some (and not all possible!) most probable errors.

Such memory modules, unlike conventional ones, have an odd number of chips. Thus, in ordinary modules used in ordinary or office computers, 8 microcircuits are most often installed. The server modules contain 9 microcircuits. Server memory with the same volume and speed costs significantly more expensive ordinary.

Winchesters

Several users can access the server simultaneously. Therefore, in addition to high reliability, the server is also required to increased performance. The servers use both conventional (electromechanical) and solid state SSD(Solid State Drive) drives.

The latter have increased performance, but they are much more expensive (for the same volume). SSD drives do not contain rotating parts. Data is written to semiconductor memory cells. Let us immediately note that you can write data to a memory cell of an SSD drive a limited (albeit large) number of times.

To reduce data access time, servers use electromechanical hard drives with high spindle speeds - up to 15,000 rpm. Such hard drives heat up more, so the problem of heat dissipation becomes even more pressing.

Server hard drives use more intelligent interfaces - SCSI and SAS, which have more functions and greater flexibility.

As a rule, hard drives in servers have the ability hot swap(hot swop), i.e. without turning off the power.

Turning off and then turning on the server is not always a quick procedure. The server “does not like” shutdowns. Sometimes, putting it into operation requires an increased consumption of nerve cells :-) The possibility of “hot” replacement is ensured by the special design of the “pocket” for the hard drive. When the drive is pulled out, the power contacts open first, and then the information contacts. During installation, the power contacts are closed first, and then the information contacts.

Reservation

On servers it is always carried out reservationse. For this there is a so-called RAID (Redundant Array of Independent Disks, a redundant array of hard drives). Information files are duplicated in a certain way. There can be several ways of duplication, so there are RAID-0, -1, -2, -3, -4, -5 and -6. Now, even if some hard drive fails, information will not be lost.

There is a hardware controller for RAID configuration. This is something that is most often not found in home or office computers. The RAID controller (more precisely, the part of it that stores the configuration) can have its own backup power source - a small-capacity battery.

Cooling

The server contains at least two processors, each of which can have several cores, several hard drives, and memory modules.

All this stuff consumes quite a lot of energy. Therefore the server needs efficient cooling system.

Cooling is carried out using radiators and , just like in a regular PC. In addition to the fans installed in the power supply(s), several additional fans are installed. All fans have increased working resource and are made on the basis of rolling bearings. You won’t find cheap “wind blowers” ​​with plain bearings there. Fans may have different dimensions depending on the design.

The cooling system is organized in such a way that not only the processor and chipset radiators are blown, but also - of course! - hard drives. All fans contain speed sensors. There are also several temperature sensors. As the temperature inside the server increases, the control system increases fan speed for more intensive cooling.

In conclusion, we note that to increase the strength of the air flow, the fans can be duplicated.

To do this, fans are installed close to each other and blow with a common air flow. If the fan malfunctions, the control circuit can sound an alarm or display service messages on the monitor screen.

Let's pause at this point. In the second part of the article we will get acquainted with power supplies, the design of servers and some subtleties that not everyone knows about. Do not miss!

Victor Geronda was with you.

See you on the blog!

Server is a computer that performs global functions that serve the work of users or the work of other computers.

Server functions

There are a huge number of functions for servers. Here are the main ones:

• file;
• mail;
• web server;
• database server;
• video surveillance server;
• Internet gateway;
• domain controller;
• network services server;
• remote access server, etc.

Thus a server is a computer that performs some function or task.

For example, a mail server is a server, or rather a computer, which manages the operation of all mail, on which all email is stored. Or, for example, a file server. This is a server, i.e. the computer on which user files are stored.

How does a server differ from a regular computer from a hardware point of view?

If you compare a server in terms of hardware and a regular computer, then servers are usually very powerful, i.e. they have powerful processors, a large amount of RAM, large hard drives, a good cooling system, etc. Those. the server can be called a powerful computer.

But why a server is a server, and a powerful computer is a powerful computer, what are the differences?

A server, essentially speaking, is the same computer, only a different program is installed on it.

It is necessary to differentiate: there is equipment for servers and there is equipment for ordinary computers.

Server equipment is usually very powerful, fault-tolerant and designed for round-the-clock uninterrupted operation without shutdown. Accordingly, it is more expensive.

Server from a software point of view

Again, a server is essentially an ordinary computer that performs some functions or tasks. For example, a mail server where mail is stored and all mail is managed; telephony server, which manages telephony and all phone-related functions; a file server on which files and data are stored, which performs storage functions, etc.

From a software point of view, a server is an ordinary computer. Those. you can take any computer and turn it into a server. But, as I wrote above, it will not be reliable and will probably work slowly.

The server function is controlled by the program installed on it. For example, if this is a mail server, then a program is installed on the computer that controls the operation of mail. The type of these programs is called a mail server. If this is a file server, then a program is responsible for its operation, which manages the file storage process and is responsible for the operation. Those. The equipment itself does not provide any server functions. You need to install some program on it that will perform this function. And the equipment itself is a hardware resource.

Roughly classified, there are 2 operating system options for servers - Windows and Linux (all *NIX-like systems). In short, the operating system is the basis that controls the computer.

Depending on the functions, reliability and tasks required of the server, the operating system is selected.

Linux has two very big advantages:

• First of all, Linux is absolutely free!
• Secondly, Linux is very reliable.