22 Oct

What is a virtual server

A Virtual Server


Whenever one opens up a web account, through an Internet Service Provider, a lot of software related services are provided. For instance, an account can come with the databases which are needed (such as SQL Server, or MySQL); the programming languages needed to develop a website (such as ASP.Net, PHP, PERL, etc.); the tools which are needed to create e-mail accounts; as well as an entire array of other software packages (such as creating an E-Commerce store, various Content Management Systems [like Joomla, Word Press, Drupal, Dot Net Nuke, etc.]).

All of these software services come to the end user via a Control Panel. This gives one the ability to manage all of these software services through one central point, and gives the look and feel of having your own server. This results in the image of actually owning a real server, with your own dedicated hardware. However, what you are really owning is what is known as a ‘Virtual Server’.

The Definition Of A Virtual Server

In order to create a Virtual Server, only one actual, physical server is used. Using specialized software, this physical server is then divided, or partitioned into multiple virtual servers. It is from within the virtual server that all of the software packages, as described up above, are installed, and available to the end user. More specifically, a virtual server can be defined as a server which shares computer resources and processing power with other virtual servers, and thus, is not a dedicated server.

One of the key components of a virtual server is the ability of it to use pooled (or shared) resources. This ‘pooling effect’ has a lot of strategic advantages to it, which are as follows:

  1. It greatly simplifies the entire network infrastructure, because of the reduced amount of actual, physical servers which are required;
  2. Software applications can be deployed quickly, which results in much greater performance and allows for software services to be available on demand;
  3. It helps to drastically reduce IT expenditures, which translates into lower costs for the for the business as well as the end user;
  4. Power consumption of the physical server can be distributed and used much more efficiently.

The Hypervisor

The ability of virtual servers to share resources amongst one another is done via the ‘Hypervisor’. This mechanism is actually a software program which allows the virtual servers to access the physical server’s Central Processing Unit (CPU). In order for a physical server to host virtual servers, it must have at least 6 to 12 core CPU’s, in order to effectively allocate the RAM, disk, and network input/output resources.

Of course, the more core CPU’s within the physical server the better, in order to ensure consistent performance across the spectrum of virtual servers which reside in it. Also, more core CPU’s allow for virtual server expansion without incurring any downtime whatsoever.

Virtual Server Schemes

There are four types of virtualization schemes which are available today:

  1. Full virtualization: Under this scheme, the hypervisor is needed to work directly with the resources of the physical server, as well as the operating system of each virtual server. The hypervisor ensures that each virtual server remains as its own entity, and also that the appropriate processing power is distributed to each virtual server;
  2. Para virtualization: With this scheme, the virtual servers are ‘aware’ of each other’s existence, and as a result, there is less dependency upon the hypervisor to monitor and allocate the appropriate amount of processing power needed by the virtual servers;
  3. Operating System (OS) Level Virtualization: With this, the hypervisor is not needed. Rather, the same type and kind of OS is used by all of the virtual servers. This is also known as a ‘homogenous virtualization environment’.
  4. LDAP Virtual Directories: This type of directory structure is used to create both Internet and Intranet related applications. This is done by sharing critical information as it relates to the business enterprise. This includes data about the employees, systems, services, and other IT components as it is made available throughout the entire corporate network.

Very often, there is confusion between an LDAP Virtual Directory and a database. The LDAP Virtual Directory gives you the additional tools, or methods, in which to update, add, or remove objects (such as the ones just described up above) from a directory tree structure. It is the database which gives you access to the LDAP Virtual Server, from which you can query the data about the objects.

Because of the ability of the LDAP’s Virtual Directory to move objects around, it possesses a number of key advantages such as:

  1. Greatly simplifying a businesses’ IT infrastructure;
  2. Much more efficient management of valuable IT resources;
  3. A substantial reduction in the Total Cost of Ownership (TCO);
  4. Effective reporting usage, with regards to IT metrics.

The following are examples when an LDAP Virtual Directory is typically used:

  1. During business merger and acquisition activity:

When business ownership changes hands, it can be very difficult to consolidate the IT assets of both (or more) organizations into one, unified entity. The LDAP Virtual Directory allows for a quick fix to this, because it can provide a unified view of multiple IT infrastructures;

  1. An LDAP Virtual Directory can consolidate multiple repositories of data:

Typically, businesses spread out their information and data across many repositories. This is done for a number of different reasons, such as security, different data file format types, and compliance. An LDAP Virtual Directory can merge of all these data repositories in real time, which can greatly aid the CEO/CIO/CFO into making sound business decisions;

  1. An LDAP Virtual Directory allows for the rapid deployment of applications:

Because of its ability to provide a unified view of all of the data repositories from within a business, software applications can be built in just a short of amount of time, and dynamically as well. As a result, this greatly simplifies the coding and QA testing processes, thus saving the business time and huge IT expenses;

  1. An LDAP Virtual Directory helps to prevent data leakage:

In any business setting, one of the key security policies is to give each employee just enough access to IT resources for them perform their respective job functions. If an employee has been given too much access, then ‘data leakage’ can occur. This is when an application (such as a database query) can literally return more confidential data than what the employee needs to have or know. An LDAP Virtual Directory greatly minimizes this security risk by only allowing the employee to access this confidential data when and where it is needed. In other words, data is not reproduced multiple times throughout the business.

  1. An LDAP Directory allows for a single point of administration:

Obviously, running multiple data repositories requires multiple views so that the information can be queried and accessed. This can be a huge burden not just from the standpoint of security, but it can also be a huge administrative burden as well, which can cost the business a lot of money. An LDAP Virtual Directory eliminates this need to have multiple views, because a single view (or point of administration) can be created very quickly and easily.