What is VPS Hosting?
What is VPS Hosting?
Virtual Private Servers (VPS) use hypervisors to provide bare-metal or operating system level virtualization for hardware partitions to make more efficient use of web server resources in a data center.
"Bare-metal" or Type-1 hypervisors are considered to provide better data isolation for security in file storage and will permit a choice of Linux, Windows, BSD, etc. on the operating system. Type-2 or "hosted" hypervisors replicate virtualization at the OS kernel level and are used with many managed VPS or cloud hosting plans.
There are numerous open source Linux virtualization platforms based on KVM, while Microsoft has Hyper-V with Windows cloud servers, Citrix maintains the Xen server framework, and VMware has a number of different hypervisor frameworks such as ESXi. Hypervisors permit the managing of multiple web servers independently on shared hardware each with isolated databases, file storage, and I/O request processing.
OpenStack, Apache Mesosphere, and CloudStack are examples of open source cloud orchestration platform software that can be used with virtualization in a data center to build enterprise solutions.
VMware, Microsoft, Parallels, Citrix (Xen Server), IBM (Bluemix), & Red Hat (OpenShift) are all leading in providing enterprise data center solutions based on VPS networks under proprietary software licensing agreements. VPS web hosting plans are considered a performance upgrade between shared hosting and dedicated servers, where elastic web server frameworks like AWS E2 and Kubernetes also make extensive use of VPS/VM partitions in cloud architecture.
VPS hosting plans allow web developers and programmers to create custom server stack software environments for web/mobile application support in production. VPS hosting plans also offer realtime web traffic and system resource monitoring tools for systems administrators.
What is VPS Used For?
Virtual Private Servers (VPS), Virtual Machines (VMs), & Containers are heavily utilized in cloud computing models of data center management. Virtualization enables a wide diversity of isolated web servers that can be managed together in load balanced networks with PHP/Python processing, MySQL database support, HTTP request caching, etc.
With virtualization it is possible to run partitions on the same web server with different isolated operating systems or PaaS/SaaS/DaaS/etc. businesses installed in the cloud. Some VPS platforms allow Windows, Linux, & BSD to be run simultaneously on the same machine by processing web traffic requests independently. Elastic scaling through virtualized replication & synchronization of databases is used to support web & mobile apps beyond the single server limit. Virtual Private Servers (VPS) are used primarily to make the most efficient use of multi-core servers with large RAID storage arrays in a data center.
Web developers and programmers use VPS plans to build custom server stack software environments and to allocate more RAM, CPU cores, storage, etc. to a web or mobile application in production. PHP, Python, Ruby on Rails, Java, Perl, & ASP.NET developers all use VPS plans to install the particular programming language extensions they need to support code on a web server.
Some systems administrators will also install Nginx (or Lightspeed / Lighttpd on BSD) as alternative server frameworks to Apache using VPS plans. For example, Nginx, Varnish Cache, & WordPress can be installed on VPS hosting plans to support up to 2x the simultaneous user traffic and pageload speeds for high traffic websites when compared to the most common Apache servers. Hadoop, Tomcat, VPN, & email servers can also be run on VPS plans. Cloud VPS platforms support web and mobile applications at scale by replicating under elastic cloud architecture and can speed up DevOps deployments using snapshots like Bitnami.
VPS plans are currently available in configurations more powerful than many dedicated server web hosting plans. VPS partitions are used extensively in the largest corporate cloud data centers in the world.
Operating System Virtualization
Operating System virtualization permits the creation of isolated VM environments that can be used as web servers with better security, network traffic monitoring, and resource allocation than both shared & dedicated servers normally provide.
Operating System virtualization refers primarily to Type-2 hypervisors like KVM or platforms like OpenVZ & Virtuozzo that share the Linux kernel (+ drivers) between partitions on the same web server hardware. This form of VPS is common in managed cloud plans where the web hosting company provides a custom web server stack software such as LAMP/LEMP pre-installed on a VM partition. Multiple customers can share a single dedicated or rackmount server with better security, file isolation, database, and programming language extension support than shared hosting provides, as well as having access to a higher level of web server resources when processing scripts like PHP, Python, or Node.js code. Some forms of OS virtualization will also permit Windows, Linux, & BSD to be installed on the same physical hardware.
One of the most popular recent innovations in cloud hosting plans is the use of operating system snapshots to install full server stack software including popular CMS code and web development frameworks. For example, instead of buying a bare-metal VPS plan and installing all aspects of the OS, Apache software, programming language extensions for the web server, database frameworks, etc. individually or via the command line, system administrators can simply choose a particular stack snapshot and deploy LAMP with the latest Drupal, Redis, Varnish, Zend, Acquia Cloud, & Apache Solr versions all pre-configured under PHP 7 settings. Entire production server portraits can be captured using this method and used for backup/restore, clone site replication, elastic scaling, load balancing with multiple website copies, etc. Snapshots work with Docker containers and Kubernetes as well as VPS plans under KVM, Xen, Virtuozzo, SolusVM, OpenVZ, VMware, etc. virtualization.
Important Elements in VPS Hosting
VPS Operating System
When choosing a VPS operating system, there are managed and unmanaged hosting plan options as well as "bare-metal" vs. shared-kernel hypervisor distinctions to consider. Many users upgrading websites from shared hosting plans for better VPS website performance (or more system resources to support web traffic) will look for a managed Linux plan with CentOS and cPanel that will provide the same ease of use in web server settings & domain name administration.
Managed VPS hosting plans with CentOS, CloudLinux, WHM, & cPanel are a popular choice and include the same stack software as shared web hosting platforms. Managed plans also include security updates for Apache web server & programming language software on a regular basis by data center professionals, saving time and money in complex systems administration.
Unmanaged VPS plans are available with a number of virtualization frameworks and hypervisors, with most users looking for "bare metal" isolation for increased security. Microsoft has also developed the Azure cloud platform for Windows servers on VPS hosting plans with elastic scalability that rivals AWS or Kubernetes. Windows is used frequently in private/public cloud orchestration for enterprise IT, whereas most small businesses running Windows servers for ASP.NET apps choose "bare metal" VPS plans.
VMware is also extremely popular in enterprise IT for virtualization, with the ability to run any Linux distribution as well as Windows servers in private, public, and hybrid cloud orchestrations. Unmanaged VPS plans can be installed with Ubuntu, RHEL, Slackware, Debian, Rancher OS, BSD, CentOS, CloudLinux, Windows, etc. as required by the user preferences or project requirements.
|CentOS||WHM, Apache, & cPanel||Software Licensing Fees|
|Ubuntu||\'Humanity to Others\'||Installation File Size|
|Debian||Base Distro for Ubuntu||No Enterprise Support|
|Fedora||Developer Frameworks||Feature/Driver Bloatware|
|openSUSE||Lightweight & Ease of Use||Extension Compatibility|
|RHEL||Red Hat Enterprise Linux||Restrictive Licensing|
|Slackware||User Community & Tools||Complex Administration|
|RancherOS||Lightweight Container OS||Minimal Extensions|
|CloudLinux||Speed, Scale, & File Size||Cost of Licensed Upgrade|
|CoreOS||Kubernetes Container OS||New & Untested Code|
CentOS Enterprise Linux is one of the most popular web server operating systems found on web hosting plans, and most companies provide licensed use of the software for free with hardware. Major web hosting companies can take advantage of bulk licensing fees for cPanel & WHM with CentOS servers, which are considered to be some of the most stable and secure Apache web server frameworks available. cPanel is primarily bundled with CentOS and WHM or WHMCS, although it is also available installed on CloudLinux or RHEL. CentOS is the most common Linux OS found on shared hosting plans.
Ubuntu is one of the most popular desktop Linux distributions which also has a web server variant as well as the Kubuntu package. Overall, Ubuntu, Debian, and Red Hat Enterprise Linux (RHEL) are commonly found in web hosting and private cloud data centers in use as web servers, with Fedora and openSUSE more popular among independent web developers and PHP/Python programmers.
Slackware has one of the largest open source development communities of any of the Linux distros with support for major and minor programming language extensions. Most of these distros have different free, licensed support, and enterprise versions.
The current trend in Linux web server OS distributions is for extremely lightweight installation requirements and integration with containers for elastic scaling of big data applications. Rancher and CoreOS both work with Docker and Kubernetes as well as other cloud orchestration platforms like OpenStack, CloudStack, CloudFoundry, OpenShift, Mesosphere, etc. Lightweight OS installations increase the number of virtual machines that can be created on data center hardware, leading to greater efficiency in production environments.
Containers provide an alternative virtualization framework comparable to hypervisors in VPS platforms. Kubernetes provides an open source version similar to the AWS E2 platform with elastic cloud capabilities and options to run multiple VPS instances inside of containers.
VPS hosting plans can be installed with a choice of Windows VPS or Linux VPS operating systems to create a custom web server stack environment for software development and operations support of websites or mobile applications in production. Most web hosting companies use OpenStack or CloudStack with KVM virtualization, Citrix Xen Server, Parallels, OpenVZ or Virtuozzo to orchestrate their VPS platforms.
Microsoft Hyper-V and VMware ESXi are both more popular in private cloud construction for corporate IT data centers. Cloud hosting solutions such as Azure, AWS, Google Cloud, etc. provide Windows and Linux VPS plans at enterprise scale to major corporations, while retail web hosting companies offer high performance, budget rate, or managed platform VPS plans to small businesses and independent publishers to provide shared access to data center services.
Microsoft vs. Open Source
The licensing differences between Microsoft and open source solutions extend to the other platforms & extensions used on web servers for cloud software development, web publishing, ecommerce, and data center management. The choice of proprietary vs. open source licensing will normally be a major factordetermining the use of Windows vs. Linux in VPS hosting. Open Source platforms offer free software and development tools without the cost of the Microsoft ecosystem, but businesses and publishers will still need to invest in experienced web development and programming teams to build custom solutions.
VPS platform security includes the operating system, network firewall, Apache server software, programming languages, installed databases, and system utilities.
Each of these stack layers contain I/O routes for anonymous public network requests that must be penetration-tested by web security professionals. Users on managed plans can expect the hosting company to keep all of the web server stack software updated with security patches, while website owners under unmanaged plans will need to keep these aspects up-to-date personally.
Similarly, network security at a data center is managed by remote professionals at layers above or below the VPS partitions.
Some web and data security measures that can be used on VPS hosting plans to protect from hacking, data theft, MySQL injection, cross-site scripting, DDoS attacks, malware, comment & form spam, etc. are:\
Transfer requests between load-balanced web servers inside the data center (such as on VPS/VM partitions) are encrypted to prevent snooping or eavesdropping.
Full Disk Encryption
All of the website files, database information, media, etc. on the VPS storage partition are encrypted.
Network Software Audits
The internal network monitoring and data center utilities are reviewed regularly for security updates.
Web Server Hardening
Where additional firewalls and web traffic network monitoring is installed on a VPS/VM instance.
Secure shell access for command line communication with a web server for purposes of Apache configuration, extension installation, file management, version control, etc.
Intrusion Detection & Blacklists
Protect cPanel, FTP, WHMCS, Ecommerce, & CMS platforms from brute force intrusion & password hacking attacks via traffic monitors & IP blacklists.
Data Backup Services
Save database and website files regularly for archive copies of information & easy restores in case of system failure.
CMS configuration including proper screening of contact forms, login panels, upload channels, and content posting are vital to prevent malicious code from being run on a server.
Website owners with misconfigured CMS scripts or out of date security versions of code risk MySQL injections particularly that can lead to the theft of an entire database. VPS admin login panels, cPanel logins, FTP connection routes, and email servers running on Apache are all common attack vectors for script bots which are programmed to target common URL structures on domains.
Anti-spam, anti-DDoS attack, anti-malware, advanced firewalls, and CDN security are all commonly provided by web hosting companies on managed VPS plans.
In summary, there are three main layers where VPS security must be reviewed in web hosting:
reviewed in web hosting:
The Data Center
internal network security, web traffic monitoring, & firewalls - may include anti-DDoS on CDN with load balancing;
The Web Server
Apache/Nginx/IIS security patches & version upgrades applied with database & programming language extensions - also brute force login protection on request channels;
The Web Script or Application Layer
CMS websites and other scripts protected from user-run PHP code, MySQL database injection on forms, cross-site scripting on forged requests, etc.
Since data center security in the cloud is managed by the hosting company, website owners need to primarily focus on the VPS settings in system administration and the web script or CMS security on production sites.
VPS Server Performance
VPS server performance averages around 1% to 3% less than "bare metal" response times on web server hardware across every I/O transfer, database process, or HTTP network request. This is the main performance difference between VPS and dedicated server plans which may be configured with similar amounts of RAM, CPU cores, or RAID storage.
Dedicated server hardware is also limited to a single tenant usage whereas VPS hardware is shared by multiple hosting customers on one partitioned web server. The latest trends in web hosting have seen companies move beyond the single server model on cloud, VPS, & shared platforms to host multiple copies of a website's files and use network load balancing software to route traffic to the hardware with the most open processing capacity for better response times.
Two other new trends with Cloud VPS plans are the introduction of elastic scalability through cloned/synchronized virtual networks that support millions of online simultaneous users of popular apps and the inclusion of "burstable" RAM on retail VPS plans to manage web traffic spikes.
Amazon pioneered the elastic cloud model based on virtualization and running multiple simultaneous versions of a website with geolocative positioning and global network load balancing on traffic request routing. CDN networks use similar software which may include anti-DDoS protection.
VPS partitions are used in public, private, & hybrid cloud orchestration at scale with data center network monitoring utilities providing integration of hardware. Burstable RAM configurations allow for momentary doubling of system resource allocations with spare capacity to meet unexpected spikes in web traffic.
The "slashdot" effect is the main problem which will lead to VPS hosted website crashes more than any other. For example, if a VPS plan has an allocation of 2 GB of RAM and 2 CPU cores with a maximum support for around 200 simultaneous users of a complex Drupal or WordPress site, a popular social media link may temporarily increase traffic to a website 10x or 100x. In these cases, the VPS will crash... unless the overflow can be managed by burstable RAM or elastic cloud scalability. In elastic frameworks, the network monitoring software simply launches a new VPS instance with a cloned & synchronized version of the website files that can manage the additional user demand. When the traffic spikes decrease, elastic server networks can automatically scale down VPS instances to conserve resource utilization in production.
The determination of either approach is based on the web traffic levels that the website will be required to support with 10,000 simultaneous users on one server considered a max limit under many Apache production frameworks.
Google has recently changed their search engine algorithms to favor website pageload speeds, leading to an increased attention to optimizing web server response times. DNS servers are often run on VPS partitions and can vary in their efficiency in responding to web traffic requests for registered domains.
SSD storage on VPS plans has been benchmarked at offering around 20-30x faster I/O speeds on web server data transfers over HDD technology. CMS website owners and any website running PHP/MySQL will receive strong performance gains for websites by increasing the system resource allocation on VPS plans over shared hosting.
Most shared web hosting plans throttle websites with more than 200 simultaneous I/O processes continually for more than 90 seconds. VPS plans with burstable RAM manage small business websites efficiently, where enterprise websites and mobile apps at massive scale most require the elastic web server functionality.
Many website owners are choosing VPS plans to implement advanced web page caching strategies with Nginx, Varnish Cache, & Redis that shared hosting plans do not normally provide. Advanced caching with Nginx and Varnish Cache can considerably speed up WordPress, Drupal, Joomla, & other CMS websites. VPS plans can also permit more advanced usage of APC, OPcache, &
Memcached with CMS websites than the system resources provided on shared Linux plans will permit. Content Delivery Networks or CDNs cache copies of a website's files in data centers by geo-location and use DNS routing to select the version closest to the web browser or user request origin. CDN services can reduce VPS website response times considerably and reduce web traffic strain on the hardware. The main advantage of VPS hosting plans is that they provide the isolation and system resources required for advanced web server stack customizations that enable better website caching for high performance web & mobile applications at scale.
Unlike most shared web hosting plans with unlimited domains, almost all VPS hosting plans include metered bandwidth limits of between 1-5 TB per month. VPS hosting plans have better resource utility panels for administration than available with cPanel where web traffic statistics can be accessed in realtime and the levels of RAM, CPU cores, or bandwidth limits can be adjusted.
Some virtualization platforms, primarily "bare metal" hypervisors, do not permit the realtime allocation or alteration of system resources to VPS partitions. Managed VPS plans including cPanel offer the AWStats service for viewing metered bandwidth on web traffic by month & day. Google Webmaster Tools is another good resource for monitoring and calculating the average traffic usage for a website by geo-location, time of day, weekend use, holiday rates, etc.
Many reseller plans also operate on VPS partitions with cPanel, WHMCS, and monthly metered bandwidth restrictions on the account. These sites can be even more critical to monitor for bandwidth limitations as the client-hosted subdomains are restricted by the total resource limit.
This means just a few domains could pull an entire reseller website offline if transfer limits are not closely monitored on a regular basis. Many Cloud VPS plans offer a "pay as you go" approach to billing where only the actual amount of CPU resources, storage, and I/O processes are billed. Systems administrators and website publishers need to calculate expected monthly traffic rates when estimating how many system resources are required to support a website in production. "Pay as you go" approaches can be more costly than fixed ratio accounts, where the trade-off is typically a more advanced VPS platform and toolset.
Solid State Drives (SSDs) have largely replaced HDD storage in web hosting across most of the major data centers in the industry. Hosting companies have published benchmark tests which show up to 30x faster speeds on I/O processes on web server requests using SSD storage over HDD technology.
Most SSD storage drives operate in RAID arrays in data centers including multiple copies of a website files for backup purposes in case of hardware failure. SSD storage can also be used as Virtual RAM (VRAM) with much higher performance standards than HDD for caching PHP & MySQL database functions in active memory. Effective use of SSD & VRAM in web servers can save significantly money in corporate IT and has been developed by Twitter in their data centers. Generally, it would not be recommended to sign up for VPS plans implementing HDD storage over SSD options in 2017 for hosting.
SSD storage can also be used in hybrid configurations to run MySQL database requests faster while HDD storage is used for media files or static HTTP requests. This technique is considered more of a cost savings and transition approach to phasing out redundant hardware.
Cloud VPS plans include SSD storage by default as well as PaaS reverse proxy page caching and load balancing with Nginx, Varnish Cache, Redis, etc. SSD storage is overall much faster in installing and provisioning VPS partitions in DevOps than HDD traditionally.
RAID storage differentials are largely based on the number of disk drives and synchronized duplicate copies of data files available. SSD storage with Docker containers, Kubernetes elastic cloud networks, and isolated VPS/VM partitions are considered fundamentals in cloud data center architecture today. Many shared Linux webhosts make extensive use of SSD storage in VRAM configurations.
VPS installation on SSD storage is much faster than HDD, where managed platforms offer a pre-installed partition available instantly after sign-up for a new hosting account and some "bare metal" partitions take longer to create. Unmanaged plans usually require the customer to install the operating system and web server stack software on a VPS plan personally. Cloud VPS plans offer snapshot services like Bitnami that can speed up web server installation and CMS application deployment considerably. Beginners will prefer managed VPS plans with CentOS and cPanel for a near identical user experience for multi-domain management as on shared Linux hosting plans.
In fact, most webhosts will offer the same LAMP web server stack software on their managed VPS plans as their shared hosting accounts. The main difference is the level of dedicated system resource allocation, such as RAM, CPU cores, bandwidth, or storage options. VPS plans also offer far more configuration options for web server customization with the command line than shared Linux or Windows hosting plans.
The VPS installation process is largely contingent on the differences between managed, unmanaged, and cloud platforms, as well as the virtualization framework employed in the data center configuration. Most webhosts will provide a tutorial with the login information in the sign-up email with further resources available in the knowledgebase.
Installing the OS on HDD storage and low RAM VPS plans can be long and arduous, whereas managed VPS plans are available instantly with the full LAMP stack from shared hosting platforms pre-installed. Setting up a cloud VPS with server stack snapshots is much easier than command line administration, as well as much quicker. In summary, it largely depends on the user preferences of the system administrator which VPS installation approach is pursued or the requirements, budget, codebase, etc. of the website to be supported by the hosting can be taken as overriding factors in decision making.
Managed VPS Hosting Features
Managed VPS plans are easy to use and will include the user name/password combination required to login and access the account in the sign-up email. Most managed VPS plans offer CentOS with cPanel, instant login, and the same software utilities found on the shared hosting LAMP stack.
The web hosting company will also provide regular web server software, installed programming language extensions, & firewall upgrades. Managed VPS plans running Windows normally include the use of Plesk for administration of domains and web server settings, while VPS plans running Ubuntu, Debian, Slackware, etc. can be administered using Webmin or Virtualmin under a free open source license.
Not all managed cloud VPS plans installed from snapshots include managed platform security, so it is important to check the auto-update settings for all web server software. Some webhosts include extra network traffic monitoring, anti-spam, anti-DDoS, or anti-malware scans in their packages, which can be useful to guard user data online against script bots and hackers (but decrease performance speeds).
The main aspect of importance when purchasing a managed VPS plan is the configuration of the LAMP stack that is pre-installed on the platform. A software package that includes Apache, Nginx, Varnish Cache, PostgreSQL, MYSQL, PHP, Python, Perl, RoR, & Node.js together is optimal for most web development projects.
Why Use Managed VPS Hosting Service?
Managed CentOS installations and web hosting companies running PaaS/IaaS plans with custom stack software normally will not permit the re-installation of the operating system on VPS plans. Users can build out custom solutions with Nginx, Varnish Cache, Redis, MongoDB, Hadoop, Kafka, Spark, etc. on managed VPS plans using command line tools like SSH, Bash, Putty, & Yum to install web server extensions.
VPS plans are one of the best ways to learn systems administration for web servers with multiple OS choices available for programming and web development. Small businesses prefer managed VPS plans for ecommerce websites due to the time savings and cost reduction in not having to hire a dedicated systems administrator.
Enterprise applications use managed VPS plans to operate cloud networks with elastic scalability, load balancing, and the ability to support millions of users at a time. Managed VPS plans can be considered as closely related to PaaS/IaaS cloud software business models for data center companies and IT majors.
Web hosting companies combine suites of software utilities for network administration; cloud load balancing optimization on web traffic; support for the latest web standards; advanced page caching; & CDN capabilities to build developer-friendly managed VPS plans that have everything needed for web publishing and LAMP programming pre-installed on the platform.
Pros & Cons of Managed VPS
In summary, managed VPS hosting is easy to use and functions similarly to familiar shared Linux or Windows hosting packages, especially on plans including CentOS, WHM, & cPanel.
Website owners need to pay around $14.95 per month to run a licensed copy of cPanel & WHMCS, with extra for Softaculous and other utilities like Railgun. Finding a web host that offers all of the software with license costs included can lead to considerable savings over independent installation of the web server stack packages.
It can take hours to build a web server with support for all of the programming languages and latest web standards. Managed VPS plans bring all of the software required for programming and web development (DevOps) into a PaaS product that is available instantly. From this, there are also many differences in LAMP stack configurations between webhosts. Buying a Managed WordPress VPS hosting plan with pre-configured Nginx and Varnish Cache installation can save thousands of dollars in web development costs for small businesses.
Managed VPS plans offer a "plug & play" or turnkey approach to PaaS web server stack software that makes web development more efficient. Many companies program custom web & mobile apps on managed VPS plans before transferring them to elastic cloud networks for production. Containers and snapshots allow for the easy transfer of an entire managed VPS platform between cloud architectures or service providers.