VDS / VPS: from hosting to clouds
The history of hosting is associated with the development of the Internet. In the 90s, service providers began to appear in different countries, specializing in hosting services in large quantities. As operating systems for servers hosting usually used reliable and affordable distributions of Linux .
Virtualization technology, developed for IBM mainframes back in the 80s, turned out to be very useful on other platforms. Virtualization software appeared - Parallels Virtuozzo, OpenVZ, VMware ESX, Microsoft Hyper-V, XenSource, Xen, KVM, HyperVM, FreeVPS, FreeBSD Jail, VDSManager, Solaris Zones.
They use different virtualization methods. VMWare virtualizes physical hardware, and SWsoft's Virtuozzo (now Parallels) is the operating system level. Guest OS instances — virtual private servers (Virtual Private Servers, VPS) — operate in the base OS environment. This technology allows you to run multiple copies of the OS in virtual containers - isolated virtual environments - on the same physical server under Windows or Linux.
Virtualization has proven to be the right tool to maximize the use of available physical resources That is why she attracted the attention of hosting service providers. Currently, according to research , 76% of companies are already using server virtualization.
')
This type of hosting services has evolved with virtualization software. The terms VDS (Virtual Dedicated Server) or VPS (Virtual Private Server), denoting a virtual dedicated server operating on the physical, appeared almost a decade ago, even in the "pre-cloud" era, although today VDS / VPS is considered a cloud service, but usually it is in accordance with the classical definitions.
In fact, both terms mean one thing - a virtual dedicated server: several virtual servers work on the same physical server, and the failure of one virtual server does not affect the functioning of the neighboring ones. Although some believe that between these services there are still differences .
Each virtual server emulates the physical work, and the VPS customer gets it at its full disposal: it has administrator rights to install the OS and software, can install applications, work with files and perform other actions as the owner of a regular server. Opportunities are limited only by allocated resources. In Russia, VPS services became widespread in the early 2000s .
VPS Alternatives - Virtual and Physical Hosting.
The so-called virtual (shared) hosting, in contrast to the VPS, provides limited configuration and management capabilities, and the user is allocated capacity on a previously prepared server. He cannot change the allocated resources, install additional software, change the server settings. Allowed to change only your content.
The resources of a physical server are divided between its users, so there may be a shortage of resources during peak loads. Usually, shared hosting is suitable for small projects and tasks that do not require significant resources and a high level of security.
In contrast to the usual virtual hosting, the virtual server VPS / VDS usually provides protection against DDoS attacks, data backup, each virtual server has its own IP address, and if necessary, you can get additional IP addresses while in virtual Hosting multiple sites often use the same IP address.
Virtual dedicated server does not have limitations peculiar to virtual hosting. You can create any number of sites, databases, domain zones, etc. There is a limit on physical resources, but VPS is guaranteed to receive them, while on a virtual hosting there is no such guarantee. As already noted, the VPS owner has full access to the system and root user rights, can install any software, and with virtual hosting only the provider can do this.
However, the cost of renting a virtual dedicated server is usually higher than the cost of virtual hosting, but significantly lower than renting a comparable physical server.
A company providing hosting services (hoster) is responsible for the reliability and quality of server connection to the network, their technical support, maintenance, equipment upgrades, data backup, security, etc. Many users are satisfied with this service, but what if the customer Do you need to install special software, manage it and generally be the full owner of your site?
Output - rental of server equipment with partial management or hosting with the installation of a client server on the provider's site. With high requirements for project resources up to a certain time, there was one option - to deploy on dedicated physical servers: leased, dedicated (Dedicated) or installed on the provider's site equipment of the customer (Colocation).
In Moscow, several large data centers have been built with the support of uninterrupted power, selection of the necessary equipment, cooling, monitoring and security systems. This type of service is offered by many large providers, but it is rather expensive.
A dedicated server is a separate physical server in the data center. All server resources and its configuration options are available to its owner. It can install any software on it, has access to all server devices, can change the operating system. If the hosting is responsible for updating the operating system and the installed software during virtual hosting, then with a dedicated server it is the responsibility of the owner.
But back to the VDS / VPS. This type of service has been actively developing for many years and is popular with customers whose websites or projects have outgrown the possibilities of virtual hosting, but do not require a dedicated server.
The advent of VPS hosting on the market has made it possible for many users to choose a more suitable option for their tasks at a more reasonable price.
Low cost with good management capabilities of their services - the advantage of VPS. Another advantage is simple scalability: you can easily add computing resources, memory, or storage capacity. These are properties of a typical cloud service, and today VPS, as a rule, is by its characteristics an IaaS service (“infrastructure as a service”). On the other hand, shared storage and communication channel means that some customers may abuse the use of resources to the detriment of others.
As already noted, the basis of this service is server virtualization. VPS customers may be offered several types of virtualization, for example, OpenVZ (at the operating system level) or KVM (hardware).
Virtualization technology is one of the important factors of choosing a virtual server: software (virtualization at the kernel level of the operating system) or hardware (complete isolation, controlled by the hypervisor). In the first case, one common system core and the OS type chosen by the provider are used: for Linux server — CentOS, Debian, Ubuntu, etc., for Windows VDS — the same version of Windows.
All virtualization systems have their advantages and disadvantages. Losses for virtualization are usually estimated at 5-10% of the total resources, but it is difficult to calculate them precisely - it depends on many factors. Among the virtual dedicated server support environments, one of the long-standing leaders is Virtuozzo technology.
In the case of Virtuozzo for an application, everything looks as if it is running on the same machine, so you can perform resource-intensive tasks. Unproductive losses to virtualization are small and constitute, according to the developers, 1-2%.
In OpenVZ, Virtuozzo, VDSmanager software virtualization. Its advantages are speed, low cost. Minus: unclear demarcation of resources, high load may affect the neighbors. If other VPS are idle, then an actively running virtual server can use all unused capacities, however, when activating another VPS, resources are “cut down” according to the specified parameters. Different VPS can vary significantly.
Plus: thanks to the use of one OS and memory, virtualization at the OS level provides the highest density (the maximum number of containers — virtual servers) on the server.
OpenVZ creates isolated operating system copies (Virtual Environments, VE) on a physical server. Since virtual servers use a common Linux kernel, the choice of operating system at the customer is limited. This is usually Ubuntu, Debian or CentOS. This technology is characterized by high performance, ease of use and server management.
Full virtualization (Xen, KVM and Hyper-V technology) is the physical separation of the kernel, where each participant can install the required OS. It is considered more reliable, because virtual servers are completely isolated from each other, a wider choice of operating systems. Cons: it takes more time to install or reboot the OS, higher pay.
For example, in KVM (Kernel-based Virtual Machine) - the so-called hardware virtualization. It creates a completely isolated analog of a physical server with its own OS kernel. Each such server is allocated its own area in RAM and disk capacity, network card. In this case, it is possible to install any OS, but resource scaling is usually limited, and the customer does not always have the ability to change the number of CPU cores or RAM capacity. Yes, and this service is more expensive.
VPS is often used for website hosting, software development and testing, for hosting content management systems - CMS (WordPress, Drupal, Joomla), especially small companies that are not available to buy or rent a physical server.
VPS is a popular type of hosting, as it provides a reasonable balance between price and features for most website owners and applications.
VPS services are currently provided by many hosters. The possibilities, price characteristics and tasks that can be solved using this type of service are very diverse. Each company providing VPS services to customers offers a different set of options. These services can be complemented by related cloud services, management and support services, security, including protection from DDoS-attacks , software licenses. The price varies greatly depending on the package of support services and administration.
A physical dedicated server is much more expensive than a virtual dedicated server, although, apart from the resources provided, the VPS is almost as good as it is. The only exception is the use of applications that require direct access to equipment. Creating a VPS server is done in minutes, and the process can be automated.
Virtual servers can be provided without support (this option is cheaper, but not to do without the knowledge of administering the OS and applications) or with support (when you do not need to do server maintenance yourself). What to choose a virtual server? This is determined by the budget and needs, the nature of the tasks and projects implemented.
There are a lot of offers of this service in the Russian market. As follows from the survey of providers of companies conducted by OSP Data , virtual servers remain the most accessible cloud service for corporate clients - they are on the list of offers from nine out of every ten providers (92.3%). In terms of popularity among customers, virtual servers rank second after e-mail: only over a third of survey participants use this service - 37.3%.
Many hosting providers provide a virtual server service running on Windows, focusing on stability , compliance with the stated parameters of the speed of the disk subsystem (for which they began to use flash arrays) and CPU, and the reliability of the Internet connection. The desire to optimize costs leads to an increase in the popularity of IT outsourcing in general, and in particular - VPS and IaaS services. According to J'son & Partners Consulting, the volume of the Russian IaaS market will increase to 7 billion rubles by 2018, despite the fact that in 2014 it was at the level of 2.5 billion. The average annual growth will be about 30%.
VPS hosting is provided in Russia by dozens and even hundreds of hosting providers. True, the results of monitoring Timeweb, conducted in April 2016, showed that the number of sites in Russia with more than 100 visits per day decreased from 301,128 in October 2015 to 270,287 sites in March 2016. This is a negative factor, because VPS in most cases is used to host sites.
According to the polls , VMware ESXi leads (57%), Microsoft Hyper-V comes second (19%), third place is shared by other virtualization tools (9%), fourth is Parallels, Citrix Xen and KVM ( by 5%). A couple of years ago, the share of VMware exceeded 80%. Due to what did Hyper-V manage to press a competitor? Consider some of the advantages of this technology as applied to VPS.
Hyper-V virtualization technology is available as a standalone, free Microsoft Hyper-V Server software, or as part of Windows Server 2012. It is based on a 64-bit hypervisor, separate from the main Windows Server 2012 OS. Each guest OS runs with its own kernel and virtual resources allocated by the hypervisor, which allows you to run different operating systems on the same physical server. This technology ensures that all the requested resources will be available to the client at any time, regardless of the activity of the server neighbors. The main difference between Hyper-V hosting and regular VPS is that hardware resources are completely isolated from other virtual machines.
Administrator rights allow the owner of the virtual server to configure the system, create users, and install software like on a physical server. Hyper-V VPS is a complete analogue of the "iron" server in terms of administration and configuration. You can install any OS, Windows or Linux, customize them as you like. In the same way, you can install any additional software, configure it, configure such hardware resources as RAM, disk space or IP address. Unlike VPS hosting, Hyper-V hosting ensures that resources can be scaled for sites or applications, and the scaling takes place on the fly without stopping the service.
The use of such a virtual server is not limited to the placement of sites. It can serve any other services, such as a database server, a terminal server , DNS, FTP, etc., as a remote workstation. With the help of Microsoft Hyper-V VPS, you can save on the purchase of licenses for Windows Server 2012, because it already comes bundled with hosting. In addition, this option allows you to reduce the cost of licenses for third-party software during collective work - you can install one licensed copy available for remote work on a virtual server. Finally, hosters offer rental of additional Microsoft software - SQL Server, SharePoint, etc.
You can easily manage the entire virtual infrastructure using the standard server management console, use the tools for disaster recovery, server consolidation and applications. The ability to back up data provides around the clock uninterrupted operation.
Hyper-V is suitable for web hosting (including high traffic sites) and application hosting, software testing and development, server consolidation, and virtual desktop deployment (VDI). All this - at an attractive price , without buying physical servers and capital investments in infrastructure.
Virtualization technology, developed for IBM mainframes back in the 80s, turned out to be very useful on other platforms. Virtualization software appeared - Parallels Virtuozzo, OpenVZ, VMware ESX, Microsoft Hyper-V, XenSource, Xen, KVM, HyperVM, FreeVPS, FreeBSD Jail, VDSManager, Solaris Zones.
They use different virtualization methods. VMWare virtualizes physical hardware, and SWsoft's Virtuozzo (now Parallels) is the operating system level. Guest OS instances — virtual private servers (Virtual Private Servers, VPS) — operate in the base OS environment. This technology allows you to run multiple copies of the OS in virtual containers - isolated virtual environments - on the same physical server under Windows or Linux.
Virtualization has proven to be the right tool to maximize the use of available physical resources That is why she attracted the attention of hosting service providers. Currently, according to research , 76% of companies are already using server virtualization.
')
What is VDS / VPS?
This type of hosting services has evolved with virtualization software. The terms VDS (Virtual Dedicated Server) or VPS (Virtual Private Server), denoting a virtual dedicated server operating on the physical, appeared almost a decade ago, even in the "pre-cloud" era, although today VDS / VPS is considered a cloud service, but usually it is in accordance with the classical definitions.
In fact, both terms mean one thing - a virtual dedicated server: several virtual servers work on the same physical server, and the failure of one virtual server does not affect the functioning of the neighboring ones. Although some believe that between these services there are still differences .
Each virtual server emulates the physical work, and the VPS customer gets it at its full disposal: it has administrator rights to install the OS and software, can install applications, work with files and perform other actions as the owner of a regular server. Opportunities are limited only by allocated resources. In Russia, VPS services became widespread in the early 2000s .
VPS Alternatives - Virtual and Physical Hosting.
Shared hosting
The so-called virtual (shared) hosting, in contrast to the VPS, provides limited configuration and management capabilities, and the user is allocated capacity on a previously prepared server. He cannot change the allocated resources, install additional software, change the server settings. Allowed to change only your content.
The resources of a physical server are divided between its users, so there may be a shortage of resources during peak loads. Usually, shared hosting is suitable for small projects and tasks that do not require significant resources and a high level of security.
In contrast to the usual virtual hosting, the virtual server VPS / VDS usually provides protection against DDoS attacks, data backup, each virtual server has its own IP address, and if necessary, you can get additional IP addresses while in virtual Hosting multiple sites often use the same IP address.
Virtual dedicated server does not have limitations peculiar to virtual hosting. You can create any number of sites, databases, domain zones, etc. There is a limit on physical resources, but VPS is guaranteed to receive them, while on a virtual hosting there is no such guarantee. As already noted, the VPS owner has full access to the system and root user rights, can install any software, and with virtual hosting only the provider can do this.
However, the cost of renting a virtual dedicated server is usually higher than the cost of virtual hosting, but significantly lower than renting a comparable physical server.
Physical hosting
A company providing hosting services (hoster) is responsible for the reliability and quality of server connection to the network, their technical support, maintenance, equipment upgrades, data backup, security, etc. Many users are satisfied with this service, but what if the customer Do you need to install special software, manage it and generally be the full owner of your site?
Output - rental of server equipment with partial management or hosting with the installation of a client server on the provider's site. With high requirements for project resources up to a certain time, there was one option - to deploy on dedicated physical servers: leased, dedicated (Dedicated) or installed on the provider's site equipment of the customer (Colocation).
In Moscow, several large data centers have been built with the support of uninterrupted power, selection of the necessary equipment, cooling, monitoring and security systems. This type of service is offered by many large providers, but it is rather expensive.
A dedicated server is a separate physical server in the data center. All server resources and its configuration options are available to its owner. It can install any software on it, has access to all server devices, can change the operating system. If the hosting is responsible for updating the operating system and the installed software during virtual hosting, then with a dedicated server it is the responsibility of the owner.
But back to the VDS / VPS. This type of service has been actively developing for many years and is popular with customers whose websites or projects have outgrown the possibilities of virtual hosting, but do not require a dedicated server.
The advent of VPS hosting on the market has made it possible for many users to choose a more suitable option for their tasks at a more reasonable price.
Features and benefits of VDS / VPS
Low cost with good management capabilities of their services - the advantage of VPS. Another advantage is simple scalability: you can easily add computing resources, memory, or storage capacity. These are properties of a typical cloud service, and today VPS, as a rule, is by its characteristics an IaaS service (“infrastructure as a service”). On the other hand, shared storage and communication channel means that some customers may abuse the use of resources to the detriment of others.
As already noted, the basis of this service is server virtualization. VPS customers may be offered several types of virtualization, for example, OpenVZ (at the operating system level) or KVM (hardware).
Virtualization technology is one of the important factors of choosing a virtual server: software (virtualization at the kernel level of the operating system) or hardware (complete isolation, controlled by the hypervisor). In the first case, one common system core and the OS type chosen by the provider are used: for Linux server — CentOS, Debian, Ubuntu, etc., for Windows VDS — the same version of Windows.
All virtualization systems have their advantages and disadvantages. Losses for virtualization are usually estimated at 5-10% of the total resources, but it is difficult to calculate them precisely - it depends on many factors. Among the virtual dedicated server support environments, one of the long-standing leaders is Virtuozzo technology.
In the case of Virtuozzo for an application, everything looks as if it is running on the same machine, so you can perform resource-intensive tasks. Unproductive losses to virtualization are small and constitute, according to the developers, 1-2%.
In OpenVZ, Virtuozzo, VDSmanager software virtualization. Its advantages are speed, low cost. Minus: unclear demarcation of resources, high load may affect the neighbors. If other VPS are idle, then an actively running virtual server can use all unused capacities, however, when activating another VPS, resources are “cut down” according to the specified parameters. Different VPS can vary significantly.
Plus: thanks to the use of one OS and memory, virtualization at the OS level provides the highest density (the maximum number of containers — virtual servers) on the server.
OpenVZ creates isolated operating system copies (Virtual Environments, VE) on a physical server. Since virtual servers use a common Linux kernel, the choice of operating system at the customer is limited. This is usually Ubuntu, Debian or CentOS. This technology is characterized by high performance, ease of use and server management.
Full virtualization (Xen, KVM and Hyper-V technology) is the physical separation of the kernel, where each participant can install the required OS. It is considered more reliable, because virtual servers are completely isolated from each other, a wider choice of operating systems. Cons: it takes more time to install or reboot the OS, higher pay.
For example, in KVM (Kernel-based Virtual Machine) - the so-called hardware virtualization. It creates a completely isolated analog of a physical server with its own OS kernel. Each such server is allocated its own area in RAM and disk capacity, network card. In this case, it is possible to install any OS, but resource scaling is usually limited, and the customer does not always have the ability to change the number of CPU cores or RAM capacity. Yes, and this service is more expensive.
What to choose?
VPS is often used for website hosting, software development and testing, for hosting content management systems - CMS (WordPress, Drupal, Joomla), especially small companies that are not available to buy or rent a physical server.
VPS is a popular type of hosting, as it provides a reasonable balance between price and features for most website owners and applications.
VPS services are currently provided by many hosters. The possibilities, price characteristics and tasks that can be solved using this type of service are very diverse. Each company providing VPS services to customers offers a different set of options. These services can be complemented by related cloud services, management and support services, security, including protection from DDoS-attacks , software licenses. The price varies greatly depending on the package of support services and administration.
A physical dedicated server is much more expensive than a virtual dedicated server, although, apart from the resources provided, the VPS is almost as good as it is. The only exception is the use of applications that require direct access to equipment. Creating a VPS server is done in minutes, and the process can be automated.
Virtual servers can be provided without support (this option is cheaper, but not to do without the knowledge of administering the OS and applications) or with support (when you do not need to do server maintenance yourself). What to choose a virtual server? This is determined by the budget and needs, the nature of the tasks and projects implemented.
There are a lot of offers of this service in the Russian market. As follows from the survey of providers of companies conducted by OSP Data , virtual servers remain the most accessible cloud service for corporate clients - they are on the list of offers from nine out of every ten providers (92.3%). In terms of popularity among customers, virtual servers rank second after e-mail: only over a third of survey participants use this service - 37.3%.
Many hosting providers provide a virtual server service running on Windows, focusing on stability , compliance with the stated parameters of the speed of the disk subsystem (for which they began to use flash arrays) and CPU, and the reliability of the Internet connection. The desire to optimize costs leads to an increase in the popularity of IT outsourcing in general, and in particular - VPS and IaaS services. According to J'son & Partners Consulting, the volume of the Russian IaaS market will increase to 7 billion rubles by 2018, despite the fact that in 2014 it was at the level of 2.5 billion. The average annual growth will be about 30%.
VPS hosting is provided in Russia by dozens and even hundreds of hosting providers. True, the results of monitoring Timeweb, conducted in April 2016, showed that the number of sites in Russia with more than 100 visits per day decreased from 301,128 in October 2015 to 270,287 sites in March 2016. This is a negative factor, because VPS in most cases is used to host sites.
According to the polls , VMware ESXi leads (57%), Microsoft Hyper-V comes second (19%), third place is shared by other virtualization tools (9%), fourth is Parallels, Citrix Xen and KVM ( by 5%). A couple of years ago, the share of VMware exceeded 80%. Due to what did Hyper-V manage to press a competitor? Consider some of the advantages of this technology as applied to VPS.
Microsoft Hyper-V: Benefits and Features
Hyper-V virtualization technology is available as a standalone, free Microsoft Hyper-V Server software, or as part of Windows Server 2012. It is based on a 64-bit hypervisor, separate from the main Windows Server 2012 OS. Each guest OS runs with its own kernel and virtual resources allocated by the hypervisor, which allows you to run different operating systems on the same physical server. This technology ensures that all the requested resources will be available to the client at any time, regardless of the activity of the server neighbors. The main difference between Hyper-V hosting and regular VPS is that hardware resources are completely isolated from other virtual machines.
Administrator rights allow the owner of the virtual server to configure the system, create users, and install software like on a physical server. Hyper-V VPS is a complete analogue of the "iron" server in terms of administration and configuration. You can install any OS, Windows or Linux, customize them as you like. In the same way, you can install any additional software, configure it, configure such hardware resources as RAM, disk space or IP address. Unlike VPS hosting, Hyper-V hosting ensures that resources can be scaled for sites or applications, and the scaling takes place on the fly without stopping the service.
The use of such a virtual server is not limited to the placement of sites. It can serve any other services, such as a database server, a terminal server , DNS, FTP, etc., as a remote workstation. With the help of Microsoft Hyper-V VPS, you can save on the purchase of licenses for Windows Server 2012, because it already comes bundled with hosting. In addition, this option allows you to reduce the cost of licenses for third-party software during collective work - you can install one licensed copy available for remote work on a virtual server. Finally, hosters offer rental of additional Microsoft software - SQL Server, SharePoint, etc.
You can easily manage the entire virtual infrastructure using the standard server management console, use the tools for disaster recovery, server consolidation and applications. The ability to back up data provides around the clock uninterrupted operation.
Hyper-V is suitable for web hosting (including high traffic sites) and application hosting, software testing and development, server consolidation, and virtual desktop deployment (VDI). All this - at an attractive price , without buying physical servers and capital investments in infrastructure.
Source: https://habr.com/ru/post/307494/
All Articles