The demands for Network Storage has always been an integral part of an enterprise network infrastructure. The explosive growth of data storage, together with corporate awareness of data management issues, has resulted in the establishment of new and emerging technologies to successfully handle current demands and to provide flexibility for future growth.

eVolution provides technical consultancy resources to effectively implement a variety of Network Storage solutions into your organisation including Directly Attached Storage [DAS], Redundant Supply of Inexpensive Disks [RAID], Network Attached Storage [NAS], Storage Area Networks [SAN] and the emerging technologies of iSCSI [IP Storage] and Tunneling of Fibre Channel [FC].

Evolution of Enterprise Network Storage [DAS to iSCSI]

Enterprise Network Storage has rapidly evolved from server-based internal storage, to server-based external storage, to serverless-based LAN storage [NAS] and finally to separate network storage LANs [SAN]. Recent developments in Enterprise Storage Management appear concentrated on developing alternative and cheaper technologies for delivering SAN-based data storage solutions, without using Fibre Channel [Tunneling and iSCSI], and the provision of equally efficient data storage backup solutions for each of the newly developed data storage standards.

Directly Attached Storage [ DAS ]

Directly Attached Storage [DAS] relates to storage attached directly to a specific server, either internally or externally.  DAS generally comprises either a RAID array [Redundant Array of Inexpensive Disks] or JBODs [Just a Bunch Of Disks] disk spanning storage solution.

Although DAS is still the most common type of storage deployed, it does has some obvious limitations. DAS relies upon the server being available and the storage being online to provide user access to the data. Due to this server-based data storage relationship, DAS solutions therefore have two points of failure, the server and the DAS device itself.

Redundant Array of Inexpensive Disks [ RAID ]

Redundant Array of Inexpensive Disks [RAID] storage solutions can be either software or hardware based and usually conform to either the popular RAID0, RAID1 or RAID5 configurations and the newer RAID10 and RAID50 configurations.

Hardware RAID arrays with dedicated controllers are usually preferred and implemented and are essential for the more advanced forms of RAID.

RAID0 provides data striping over multiple disks but does not provide redundancy. RAID1 provides either disk mirroring or disk duplexing, and provides redundancy by mirroring/duplexing physical disks. RAID5 provides data striping with parity over three or more physical disks. Fault tolerance is provided by a RAID5 array recovering from the loss of a single disk within the array.

Newer hardware RAID configurations include RAID10 and RAID50. These newer configurations are based upon variations of RAID0, which provides optimum I/O performance, but no redundancy. Combining RAID0 with fault tolerant RAID configurations provide the ultimate data storage solution - optimum I/O performance and fault tolerance.

RAID10 provides a combination of RAID1 [mirroring] and RAID0 [data striping], creating a striped set that writes to mirrored disks. RAID50 combines RAID5 [data striping with parity] and RAID0 [data striping], creating a striped set across RAID5 stripe sets with parity.

Network Attached Storage [ NAS ]

Network Attached Storage [NAS] enterprise solutions are serverless-based LAN storage. NAS is a storage pool - the NAS device or appliance, also known as a Filer, is directly attached to the existing network, therefore removing the server from the equation in terms of management and point of failure for your online storage.

However, NAS appliances are not ghost-driven, they include a very lightweight task-specific operating system [usually UNIX or Windows based] which can be quickly and easily managed - a thin-client storage server.

Major benefits of NAS include: [1] Connects directly to the LAN, uses standards network protocols [TCP/IP, IPX] and supports multiple UNIX/Windows file systems [NFS, CIFS] [2] Provides a cost effective solution of storage located in a single place for all to use - when more storage is needed, simply add it into your existing NAS solution [3] Easy to install, administer and backup - NAS appliances can be backed up by using SCSI ports directly connected to offline storage, providing a LAN-free backup solution, thereby reducing precious bandwidth.

As NAS appliances attach directly to your production LAN, competing for precious bandwidth, such storage solutions should be developed in harmony with your high-speed network infrastructure changes. With today's Gigabit Ethernet networks, NAS appliances are an efficient and flexible solution to your growing enterprise storage requirements.

Market leaders in the provision of innovative and comprehensive Network Attached Storage [NAS] data storage solutions, include Network Appliances, HP/Compaq StorageWorks and IBM TotalStorage.

Storage Area Networks [ SAN ]

Storage Area Networks [SAN] solutions removes data storage from the production network and creates a separate storage network. SANs are high-speed, dedicated networks that join together any combination of storage devices [RAID, tape or optical libraries] to the front-end production servers.

SANs enhanced backup and restore performance eases congestion on an enterprise's LAN, freeing it for normal business activities and communications.

Fibre Channel [FC] is the key to the success of SANs - FC is a standards-based communications protocol that can be implemented in either fiber-optic or copper formats, provides performance from 266mbps to more than 4gbps, support for distances up to 10km and the ability to carry multiple existing interface command sets, including IP and SCSI.

Servers are connected to clients via ethernet, and the SAN-side is usually connected via FC. Storage devices are connected via SCSI to the FC network. Fibre Channel architecture has developed three topology options for physically connecting devices: Point-to-Point, Arbitrated Loop and Switched Fabrics. Choice of architecture dependent upon proposed number of connected devices.

Major benefits of SANs include Scalability [pay as you grow], Availability [resilient networks and end-to-end availability], Performance [multi-Gigabit throughput] and Security [SAN zoning].

Market leaders in the provision of innovative and comprehensive Storage Area Network [SAN] data storage solutions, include Brocade, HP/Compaq StorageWorks and IBM TotalStorage.

Emerging Technologies [iSCSI and Tunneling]

Tunneling will continue to use Fibre Channel [FC], the current standard for SAN connectivity. Control codes and data that ordinarily travel over FC mediums will be converted to IP packets. Those IP packets will then go between one FC SAN to another FC SAN, permitting a break in the need for FC connectivity between distances - ideal for disaster recovery solutions that may span huge distances. This technology will use existing IP standards with the tunneling of FC to increase distances, without using only FC.

iSCSI will encapsulate SCSI commands and data in IP packets for use on LAN ethernet networks and over WAN/Internet distances. The combination of iSCSI and Gigabit Ethernet is predicted to seriously rival Fibre Channel in the future. The challenge with iSCSI development is to overcome the risk of losing the ability to guarantee the quality of service inherent with Fibre Channel, as well as potentially losing the simple interfaces of SCSI.

Following the design and implementation of your chosen network storage architecture, eVolution can provide technically qualified engineers to maintain, manage, configure and troubleshoot  your DAS, RAID, NAS and SAN devices and peripherals to maintain optimum flexibility and efficiency of your organisation's network storage infrastructure.

eVolution has the commercial experience and technical competence invested within it's System Engineers to successfully manage your strategic IT integration project or programme.

To assure you of our dedicated management and support of your project,  unlike other IT computer consultancies, eVolution guarantee only to contract to a single client organisation at a time, consequently their is never a conflict of interest between competing clients for our valuable technical and managerial expertise. A true One2One business relationship.

Please visit www.netapp.com for further information on available Network Appliances NAS devices.

Please visit www.brocade.com for further information on available Brocade SAN Silkworm fibre channel switches.

Please visit www.ibm.com for information on IBM TotalStorage hardware/software products and services.

Please visit www.hp.com for information on HP/Compaq StorageWorks hardware/software products and services.

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