ДИСС

As for today the storage "grown" from a simple set of disks on the workstation to full individual system and formed the three main types. There are a system with direct connections to one or more servers (Direct attached storage, DAS, and Shared DAS), network-attached storage (Network attached storage, NAS) and Storage Area Network (Storage Area Network). There is also a system, combining elements of several species, such as Network & SAN attached storage.

Systems with direct connections are used to increase disk capacity of servers, a relatively small applications and clustering.

Entry-level systems, usually connected to interface SCSI (any more popular in these days - SAS), or for Fiber Channel, and contain hard drives SAS / SATA and SCSI. Many systems allow you to install both SAS and SATA drives simultaneously, which allows users to organize high-speed SAS array for critical speed and reliability of applications and a capacious and inexpensive array of SATA drives in a single package. The high standardization and continuity of technology allows even entry-level systems to install additional disk shelves, redundancy and hot swap controllers, drives, power supplies and so on.

Network storage systems, in contrast to DAS and SAN systems, provide access to the file level, rather than blocks. They are integrated into existing network infrastructure (Ethernet), and provide file services, printing services, etc., relieving the main server of the company from these problems. Upper level system offers backup software partitions and arrays make it easy to manage and integrate with key server applications - such as servers, databases, SAP, MS Exchange, Lotus, etc.

Storage Area Networks presuppose the existence of a dedicated network for storage systems and servers connected to them. There are two types of SAN - built on Ethernet (protocol iSCSI) and based on Fiber Channel. Systems of the first type are much. Latter, the same pay-per-performance has the high initial cost. As for today, many of the leading players in the market offer SAN system, combining modules using both technologies, allowing end-users to save on implementing Fiber Channel infrastructure initially, and then move to FC environments where growth problems demands it.

An important feature of storage within the SAN, as well as in NAS systems - is a software that provides the functions of preservation and restoration of data synchronization with remote storage and creating resilient environments that interact with enterprise applications.