VPSit -

Virtual Private Server (VPS) / Virtual Dedicated Server (VDS)

A virtual private server or VPS (also known as a virtual dedicated server, a VDS, or virtual server) is a method of partitioning one physical server into multiple servers. Each one of these servers has the appearance and capabilities (with it's own allocated resourced) as it if were running it's own dedicated server. Each VPS can run its own full-fledged operating system, and each server can be independently rebooted.

A server can be devided (and a VPS created) in two different ways; software or hardware.

Software based VPS: Sometimes called OS-level or shared OS virtualization, OS virtualization virtualizes servers on the operating system (kernel) layer. This method of virtualization creates isolated partitions, or virtual environments (VEs) on a single physical server and OS instance to utilize hardware, software, data center and management efforts with maximum efficiency.

In a software based VPS, the virtual machines share the same kernel and actually require the main node's resources (CPU, memory, etc.). The software based VPS is preferred in the web hosting industry as the resource quotas can be changed dynamcically in real time without the nead of restarting the invidual node (the VPS). The industry leading software versions are Virtuozzo which is was VPSit uses (a product of SWSoft), and HyperVM (a product of LXlabs). There is also an open source version of a software based VPS call and openvz (which is the core kernel of both virtuozzo and hypervm)

Hardware based VPS: The hypervisor model has a base layer (usually a thin Linux kernel shown here as a hypervisor or standard OS) that is loaded directly on the bare server. To allocate hardware and resources to the virtual machines, all of the hardware on the server must be virtualized. The next layer up shows each chip, board, etc. must be virtualized so that it can be assigned to virtual machines. Once in the virtual machine itself, there is a complete copy of an operating system and finally the application or workload.

In a hardware based VPS, the actual hardware is partitioned so not burst or dynamic changes of quota are allowed. The quotas set in your VPS are hard and only modified after a restart. This kind of environment can sometimes be considered more secure as you will not be sharing any burst room and you are not relying on another layer of software to keep your VPS running. However if the software based VPS provider (like Virtuozzo) keeps their systems up-to-date then there is generally a no larger security risk in using a software based VPS. Hardware based VPS is generally very useful in enterprise/commercial usages. Popular hardware based VPS providers are Microsoft Virtual Server, VMWare, and Xen. VPSit uses and specializes in Xen and VMWare.

The two diagrams below show the hypervisor or hardware virtualization technology in comparison to OS virtualization.

The Software based VPS (OS virtualization mode)l is streamlined for the best performance, management and efficiency. At the base resides a standard host operating system, in the case of Virtuozzo that includes Windows and Linux. Next is the virtualization layer with a proprietary file system and a kernel service abstraction layer that ensure isolation and security of resources between different virtual environments. The virtualization layer makes each virtual environment appear as a standalone server. Finally, the virtual environment itself houses the application or workload. The best part is that you can upgrade your VPSs with little to no downtime and very little costs.

Even though VPSit uses Virtuozzo, Xen, and VMWare for their VPS management most of the VPSs tend to be Virtuozzo by SWSoft since they give the most amout of burst room for users for hosting. You will want to contact sales if you are interested in getting a Xen or a VMWare VPS as most (of not all) of the VPSs listed online are using Virtuozzo.

Easy interface to fully manage your VPS

To make the administration of the VPS easier many VPS providers have an easy to use interface where users can reboot their VPS and even restore from a backup. VPSit uses the the powerful tools part of HSPComplete to accomplish these tasks.

With the VPSit version of HSPComplete you can:

Do full backups of your VPS
Restore your VPS from a backu
Install and uninstall from a preset list of applications
Upgrade your VPS
Make payments associated to your VPS

What does SWSoft's Virtuozzo do?

SWsoft’s Virtuozzo virtualization software is used to partition a single physical server into many isolated virtual environments, creating the VPSit service. Each virtual environment is completely isolated and behaves exactly like a real networked server, complete with its own set of init scripts, users, processes, filesystems, etc. Each virtual environment can have different applications and the root user is in full control, just like a dedicated server.

What is a VPS from VPSit?:

VPSit VPS hosting is VPSit''s brand for its hosting solutions based on Virtual Private Server (VPS) technology . VPSit's extra VPS control allows us to give all users the ability to dynamically migrate customers from one VPS to another or even to a fully dedicated server (with VPSit Dedicated) seamlessly and with virtually no downtime and migration costs.

In a close partnership with SWsoft, VPSit developed our Virtual Private Servers using Virtuozzo technology. The resulting virtual private server brought about a new standard for performance, reliability and flexibility. No other company can compare with the performance, reliability and ease of manageability that VPSit provides.

VPSit VPSs have Dynamic Scalability

Complete hosting environments can be quickly moved between VPSit VPS hosting plans or even to a VPSit Dedicated hosting. In fact a VPSit VPS, with hundreds of live sites, can be transferred to a larger VPS plan or even VPSit Dedicated physical server with only a few seconds of downtime. This will allow you to rapidly scale your services to suit the changing dynamics of your e-Business and accommodate growth. No matter what your growth is, VPSit can work with you to guarantee you the best plan to keep you on buget and with optimal performance.

VPS has Dedicated Performance

Each VPS comes with dedicated server functionality - root access, ability to install custom applications, etc.. You have dedicated resource utilization, monitoring and control of the full root filesystem.

VPSit has Fair Share Technology

VPSit uses Virtuozzo's patented Fair Share technology to dynamically distribute resources between VEs (virtual environments) on the same physical host. Fair Share technology allows VPSit to set guaranteed minimum resource allowances for each type of VPS server. At the same time, Fair Share technology gives each VPS access to unused physical resources. This way no single VPS server can monopolize Bandwidth, RAM or CPU resources and yet each VPS can maximize its performance by tapping into idle resources.
In practice, DDS servers can burst far above guaranteed resource allowances for better overall performance while maintaining guaranteed performance levels. This is not possible with lesser VE technologies.

A VPS from VPSit:

Has its own processes, users, files and provides full root access
Has its own IP addresses, port numbers, tables, filtering and routing rules
Has its own configuration files for the system and app software
Use own versions of system libraries or modify existing ones
Delete, add, modify any file, including files in /root, and install own application software or custom configure/modify root application software

Virtualized services have many benefits over a dedicated server:

Cost: All of the functionality of a dedicated server at a fraction of the cost.
Reliability: Bundled incremental backups ensure your data remains safe.
Manageability: Tools help you add applications, change and upgrade your service instantly.
Burstability: Get the available resources you need when you need them.
Flexibility: Instantly increase your service plan to provide for more resources as you grow, easily move to a new more powerful server.

Virtualized services have many benefits over shared hosting:

Control: With administrative or root access, you can modify server configuration files, install applications or modify system software.
Security: Your file system is not accessible or viewable by any other customer, your files are ensured full privacy and security.
Isolation: You are fully isolated from other users and actions on the server. No other customer can slow down or affect your service.
Performance: Your resources may be guaranteed based on your plan, nothing else on the server will affect the performance of your VPS.

Disadvantages

With a software based VPS you are not given the ability to sometimes add your own custom kernel. This can limit you if you are running an applcation that needs special kernel optimizations configured. However the general kernel that comes with a software VPS tends to have everything a normal hosting provider would ever want.
You are still sharing the same physical box as multiple users so a large enough attack can cause loss of ability to contact the server since that port is saturated. VPSit works around this problem by stopping all attacks "before" they get to the server with inline DDoS IDS / IPS devices.