Storage Virtualisation

Virtualisation is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage Virtualisation is commonly used in Storage Area Network (SAN). The management of storage devices can be tedious and time consuming. Storage virtualisation helps the storage administrator perform the tasks of backup, archiving, and recovery more easily, and in less time by disguising the actual complexity of the SAN. Users can implement virtualisation with software applications or by using hardware and software hybrid appliances. The technology can be placed on different levels of a storage area network.

Ultra 3 and Ultra 2

Ultra3 SCSI will differ in five key areas from Ultra2 SCSI, according to STA officials.

First, transition clocking doubles data throughput to 160 megabytes per second. This is done by sending two pieces of data per clock pulse instead of one, thereby doubling the throughput without increasing the processor's clock speed.

Cyclic redundancy check will improve data-transmission reliability via an enhanced error-catching scheme.

Domain validation lets the host and device communicate to find the optimal data speed, and identifies the topology and configuration of the SCSI bus.

The other new features include packetization for transferring multiple commands and threads of data per cycle, and quick arbitration select to reduce disconnect and reconnect time on the bus.

Ultra3 SCSI will be backward-compatible with Ultra2 SCSI, allowing Ultra2 SCSI devices to connect to the bus without affecting performance.

E-Commerce

E-Commerce is the buying and selling of goods and services on the Internet especially the world wide web. E-business ans E-tailing also describe it. The amount of trade conducted electronically has grown rapidly with the spread of internet. E-Commerce includes electronics funds transfer, supply chain management, Internet marketing, Online transaction processing, Electronic data interchange, automated inventory management systems and automated data collection systems
Online retailers are sometimes known as e-tailers and online retail is known as e-tail.

The e-commerce services and products can remain physical and ordered, delivered and paid by physical means or transactions that are entirely virtual and involve marketing, advertising, ordering, delivering, purchasing and servicing products and services entirely over the Internet.

At present e-commerce accounts for only a very small percentage of global trade and commerce. Although transactions between large corporations and their suppliers and customers account for the largest share of e-commerce today, a growing number of small and medium sized enterprises are beginning to implement Internet Business Solutions.

Digital Signature

Digital Signature is a sort of cryptography. It deals with keeping data private. It a method of converting data and messages into a different form ie encrypting it with the help of a key.
The message can be converted using a code where each character or a group of characters is substituted by a different one or by using a cipher where the message as a whole is converted rather than individual characters. It basically deals with encryption, decryption and authentication.

Stream Computing

Stream Computing deals with pulling in streams of data, process the data and stream it back out as a single flow. This helps to analyse multiple data streams from many sources live. It uses software algorithms to analyse data in real time as it streams in to increase speed and accuracy when dealing with data handling and analysis. IBM has a stream computing system called "System S". It runs on 800 microprocessors. It allows software applications to split up tasks and then reassemble the data into an answer.
Stream Computing harnesses the tremendous processing power of graphic processors for high performance, data-intensie computing in a wide range of scientific, business and consumer applications. providing organisations the ability to process massive amounts of information in significantly less time.
In certain applications requiring massive vector operations, Stream processing can yield several orders of magnitude higher performance than a conventional CPU. These applications may include Life Sciences, Scientific Research and Enterprise applications.

SCSI - Small Computer System Interface

SCSI is a set of standards or something like a protocol to connect a computer and pheripheral devices. There are several features of it:

• SCSI is an intelligent interface , it hides the complexity of physical format. Every device attaches to the SCSI bus in a similar manner
• SCSI is a peripheral interface - it can connect to 8 or 16 devices to a single bus. There can be any number of hosts and peripheral devices but there should be atleast one host.
• SCSI is a buffered interface - it uses hand shake signals between devices, it can transfer only real data and does no error checking and correction. All those are done in a buffer.
• SCSI is a peer to peer interface- Communication can be from host to host , host to a peripheral device, peripheral device to a peripheral device