netwyman

High availability used to be expensive, requiring both specialized software and redundant hardware. Today it almost grows on trees, but you need two key ingredients: virtualization and network storage. By creating a virtual server farm across multiple physical servers, and storing all of your virtual machines on a central SAN or NAS, you can ensure that the failure of any given piece of physical hardware will not bring down your virtual environment. We recently created a highly available virtual server cluster based on the free edition of Citrix XenServer; this article outlines the process step by step. Although the obvious choice for any enterprise-grade virtualization deployment is VMware vSphere, I chose XenServer for two reasons. First, we're cheap. We don't like spending money on things that we can get for free. Second, and more important, the licensing of VMware is extremely confusing; we're never sure what exactly is required to be properly licensed. (I guess...

Citirix XenServer is a hypervisor platform that enables the creation and management of virtualized server infrastructure. It is developed by Citrix Systems and is built over the Xen virtual machine hypervisor. XenServer provides server virtualization and monitoring services. It is available in a 64-bit hypervisor platform and can be executed on the entire x86 series of processors. Cirtix XenServer is among the virtualization solutions provided by Citrix Systems, which consolidates a physical server's computing power into multiple virtual machines, all emulating as a standard server. Citrix XenServer is built to provide the operational requirements of a standard server and supports most server operating systems, such as Linux and Windows Server, on guest server machines. Through its virtual machine monitoring component, Citrix XenServer manages the allocation and distribution of physical server computing resources among virtual machines and administers their performance an...

Design Issues in Network Layer Network layer is majorly focused on getting packets from the source to the destination, routing error handling and congestion control. Before learning about design issues in the network layer, let’s learn about it’s various functions. Addressing: Maintains the address at the frame header of both source and destination and performs addressing to detect various devices in network. Packeting: This is performed by Internet Protocol. The network layer converts the packets from its upper layer. Routing: It is the most important functionality. The network layer chooses the most relevant and best path for the data transmission from source to destination. Inter-networking: It works to deliver a logical connection across multiple devices. Network layer design issues: The network layer comes with some design issues they are described as follows: 1. Store and Forward packet switching: The host sends the packet to the nearest route...