SAN and NAS SAN A storage area network

SAN and NAS

SAN A storage area network (SAN) is a secure high-speed data transfer network that provides access to consolidated block-level storage. SAN makes a network of storage devices accessible to multiple servers. SAN devices appear to servers as attached drives, eliminating traditional network bottlenecks. SANs are sometimes also referred to as SAN storage, SAN network, network SAN, etc.

Features of SAN Separate network handling storage needs. Detaches storage tasks from specific servers. Shared storage facility across high-speed network. Hard disks, tape libraries, CD arrays. Improved client-server storage access Direct storage to storage communication for backup Centralized management Storage consolidation/shared infrastructure High availability and disaster recovery High bandwidth Scalabilities Shared data

Principle, Goal and Interest Principle: centralized storage resources and federate them with high speed network. Goals: simplified management, autonomous storage units with end host. Interests: ease of data management (store operations, backups. Restore…. )

Storage Controller-The heart of SAN It is a software/hardware entity that manages one or more storage containing entities and provides a simple and abstract view of the managed devices. Storage controller-Location in the SAN: It can be found 1. Internal to the host/server Disadvantages: Does not allow sharing of the storage system between multiple hosts/servers. 2.

Benefits of SAN In general, there a few basic areas where employing a SAN can reduce overall storage costs significantly: Availability: SAN storage is in general more reliable than DAS attached disk. This can save your company money by avoiding application outages. The cost of an hour of application downtime varies from company to company but can exceed millions in some cases. Disk utilization: When buying server-attached storage most people buy more than they currently need so they can "grow into" the storage. The space that is unutilized is wasted until it is needed. In SANs, that space can be "assigned" to any server that needs more storage, thus deferring new storage purchases. Management: Using DAS you need to manually install new disks to add storage. In a SAN you can remotely assign it to a server. No downtime and perhaps not even a reboot is required if the OS can handle it. You can manage ALL your storage GLOBALLY from a single console. Backup: Using snapshots and data replication can save your backside when disasters happen and using a SAN for centralizing data backup can improve recovery time dramatically while reducing overall costs by sharing tape resources and eliminating

NAS A network-attached storage (NAS) device is a server that is dedicated to nothing more than file sharing. Network-attached storage does not provide any of the activities that a server in a server-centric system typically provides, such as email, authentication or file management. Description: A NAS unit is a computer connected to a network that provides only file-based data storage services to other devices on the network. Although it may technically be possible to run other software on a NAS unit, it is usually not designed to be a general-purpose server. For example, NAS units usually do not have a keyboard or display, and are controlled and configured over the network, often using a browser. A full-featured operating system is not needed on a NAS device, so often a stripped-down operating system is used.

Benefits of NAS 1. Improve performance 2. Reduced storage capacity requirement 3. Increase reliability 4. Reduce management cost 5. Improve scalability 6. Improve security 7. Increase data availability 8. Eliminate backup issues