The IP Storage Area Networks (IP SANs)

s of iSCSI IP SANs use iSCSI to allow one set of data to be shared between one or more servers and one or more storage systems, all on one network. The block Begin With The Basics data is distributed by the switch, at the heart of the IP SAN.

What is iSCSI? Storage System iSCSI stands for SCSI, a protocol that allows SCSI data blocks to be moved across an Ethernet, or IP network, rather than a specialized iSCSI network. An IP SAN is a iSCSI created using iSCSI.

What are Data Blocks and iSCSI Where are they Used? iSCSI Ethernet Database, email and some other applications Switch generate very large amounts of data. So, this data is Server divided into blocks to keep the data in manageable sets for storage, access, and transfer. In contrast, Storage System because file data (like in Microsoft Word) is more manageable to handle, it is kept together as one unit.

Why Do We Need iSCSI?

Typically, block data is stored to disk drives or storage systems that are directly attached to servers, called Direct Attached Storage (DAS). This scenario is inefficient because this data can be accessed only by the server to which it is attached — and once a server runs out of space, you can’t add more storage capacity. A more efficient way to share data is with an IP storage area network (SAN). An IP SAN uses existing Ethernet lines to create a network that allows servers to access the data stored on one or more storage systems. This “shared storage” scenario allows you to store data on more than one storage system and use idle storage capacity as you need it.

Another alternative to DAS is a Storage Area Network (SAN). But, Fibre Channel SANs are expensive and complex to maintain, and require separate networks from the Ethernet networks that already exist in corporate envioronments. An IP SAN, on the other hand, allows block data to be shared and managed on the existing Ethernet networks — saving time and money because there’s no new infrastructure to install, learn, and maintain.

Still Have Questions? Ask the Storage Advisors at http://storageadvisors.adaptec.com The s of iSCSI iSCSI Glossary

Block Data Data that is divided into blocks, typically generated by applications including database and email. Direct Attached Storage Storage that is directly attached to a server (and does not use a network connection). Ethernet The standard communications and data network currently used for the vast majority of business operations. Fibre Channel A high-speed technology for connecting servers and Block Options storage devices that allows data transfer at rates up to 4Gb/s, but is expensive and complex to maintain. File Data Unstructured data stored as one unit, typically generated by Description Advantages Disadvantages applications including spreadsheet, presentation, and word processing.

Direct Attached Disk drives or storage Installation is simple Difficult to share data, Gigabit Ethernet The current standard for Ethernet, which allows data to Storage (DAS) systems that are difficult to expand be transferred at speeds up to 1 Gb/s. directly attached to capacity as data grows Unified Storage Architecture A feature of the GuardianOS operating the server that system that allows both block and file data to be stored on a standard generates the data Snap Server networked storage solution. Packet A unit of data that has been formatted for transport across the IP SAN Cost-effective storage Uses existing Ethernet Transfers data at Ethernet network and typically consists of a header that lets the network (uses iSCSI protocol) area network that networks 1Gb/s instead of know the packet is beginning, a payload that actually contains the data, allows data to be the 4Gb/s of Fibre and a trailer that lets the network know the packet is ending. shared across No new infrastructure and Channel Storage Area Network (SAN) A storage architecture that connects servers multiple servers and no new IT resources or and storage devices via a network. storage systems training required

Good for long distance data transfer — Broad iSCSI Options Fibre Channel SAN High-speed storage Highest performance and Complex and costly - area network that highest reliability requires an entirely Adaptec delivers iSCSI solutions that meet a variety of allows data to be new infrastructure and storage needs. When you need to store and move only block ™ shared by multiple specialized IT training data, Adaptec OnTarget software provides an easy and servers and storage to maintain that cost-effective way for solution providers to turn any standard systems infrastructure server into an iSCSI storage system. Our Snap Server by Adaptec product line gives you iSCSI-enabled options for Not good for long distance data transfer storing file data or block data, or storing both block and file data on a single server.

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