virtual server

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virtual server

(World-Wide Web)
A configuration of a World-Wide Web server that appears to clients as an independent server but which is actually running on a computer that is shared by any number of other virtual servers. Each virtual server can be configured as an independent website, with its own hostname, content, and security settings.

DNS maps the hostnames of all virtual servers on one physical server to its IP address. The web server software then uses the "Host" header in the HTTP request to determine which virtual server the request was for, and then processes the request using that virtual server's configuration.

Virtual servers allow Internet Service Providers to share one computer between multiple websites while allowing the owner of each website to use and administer the server as though they had complete control.

virtual server

(1) See server virtualization. Contrast with virtual host.

(2) A virtual machine environment from Microsoft for Windows servers. See Microsoft Virtual Server.

(3) Multiple servers that appear as one system image to the operating system or to the network administrator. See network virtualization.

(4) One instance of a Web or application server running in a single computer that is hosting multiple Web or application servers. See Web hosting.

(5) Multiple servers that appear as one server for load balancing. For example, all clients use the IP address of the virtual server, which uses address translation to point to a real server based on its load balancing algorithm.

Load Balancing
For load balancing, all clients use the address of the virtual server, which is substituted with the address of one of the real servers. The selection algorithm could be simple round robin or based on the current load of the servers. See round robin.
References in periodicals archive ?
IBM today announced plans to release a new virtual server offering, called Dedicated Hosts, that provides enterprises with more precise placement control over their cloud workloads.
Time saving--Speaking of server provisioning, bootable images and virtual server templates can be kept on-hand for when they're needed.
It does this by automatically generating data from communications pathways between physical servers as well as combined data from virtual servers produced by communications, and then analyzing the relationship between the virtual system and physical network communications pathways based on relationships, such as whether each virtual server resides in a respective physical server.
Middle East enterprises should understand the fundamentals of virtual server data protection as they adopt data centre virtualisation, said an expert.
org has proudly celebrated it's 10th anniversary, and to mark the momentous milestone, the company has announced several new virtual server plans that will allow it's customers to take advantage of the best hosting service at a low price.
The analyst house said 91% of respondents to a recent survey are currently using virtual server technology for production workloads, compared with 78% last year.
Prior to deploying Isilon scale-out storage, Webtrends didn't have a central, shared storage resource capable of scaling in-step with its growing virtual server environment, which limited application performance and complicated both storage and virtual server management.
lt;p>That may be, but one area that is proving to be tricky for IT managers is dealing with the growth of data duplication within virtual server environments.
Virtual servers offer the flexibility, but at the same time if a single physical server containing multiple virtual server fails, then impact of data loss is enormous.
Over the same five-year lifespan, a virtual server has a cost of $180 for power and cooling, and only $1,400 for its share of the hardware.
This guide describes how to administer Microsoft Virtual Server 2005 R2, including Service Pack 1, covering its installation and management, project methodology, and infrastructure management.
It provides data center engineers and test teams with the visibility they need into virtual server traffic.

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