Storage Solutions

If you would like advice or assistance regarding storage contact the CONCENTRIC Engineering Services team on 1300 658 758.

DAS

DAS is the most simple version of Direct Attached Storage. Optimised for single isolated processors and minimal start-up cost, DAS generally comprises a single disk drive or tape drive connected to one processor (host). Some disk systems enable the configuring of subsets or partitions of capacity with each partition assigned to a different host. This capacity allows for enterprise-class disk systems to be effectively configured as DAS by assigning subsets of the internal disk capacity to selected hosts. DAS is identified as a minimal network. The hard disk drive for an isolated processor such as a laptop, a desktop PC or a single server in a small business, usually located inside the processor itself, represents the simplest form of DAS.

Perfect for smaller businesses or departments, DAS may not be the ideal solution for organisations with multiple processors as a more complex networking solution may prove to be more cost effective at a wider business level. For individual use or small organisations however, DAS is a cost effective, robust storage alternative with the capacity to expand for large business through direct connection via SCSI or point-to-point Fibre Channel paths. Disk system partitions can be manually reassigned from one processor to another as required, a process still identified as a DAS approach to storage.

NAS

A Network Attached Storage (NAS) is a high performance storage device. Residing on a Local Area Network (LAN) rather than sitting behind it (as with SAN), NAS shares the network with non-storage traffic. Easily installed, a NAS provides instant access to greater storage capacity, to all users of a LAN . Although usually based on an Ethernet LAN , NAS can reside on any network that supports the IP based products that NAS uses. Generally supporting disk storage, NAS sometimes provides CD ROM in an integrated package and tape drives for backup purposes. Capacity pooling is available among all hosts using NAS, which makes it a more efficient method of additional storage for multiple users, than the purchase of individual volumes (as in DAS). Pooling avoids the problem of some users working with too much or too little capacity and can minimise manual reassigning of capacity among users.

NAS offers the benefit of distance as it is attached over a network rather than located within the processor (as in DAS) but it does not offer large capacity for sharing of files across multiple appliances (as in SAN). However its ease of installment and management make NAS the storage solution of choice for many organisations.

SAN

Access: greater distance between server and storage with increased availability and enhanced performance. Numerous processors can be connected to the same storage device rather than the conventional built in device attachment facilities.

Consolidation: replaces multiple independent storage devices by pooling disk and tape space on minimal devices with shared capacity. Storage can be managed from a single point of control although the multiple SAN devices will appear as a single pool of storage available to all processors in the network. While allowing for maximum scalability, controls can also be implemented to allow selected hosts to identify their storage via zoning and LUN masking.

Protection: rapid SAN backups are able to be performed, bypassing the slower LAN and server-free backups can let disk storage 'write itself' directly to tape without overloading the processor.

Data Sharing: the sharing of data reduces multiple file copies, increases accessibility to the most current information and reduces or eliminates the need to transfer data copies between servers via the LAN.