This edition applies to the products in the IBM Storage Area Networks (SAN) portfolio. Note: Before using this information and the product it supports, read the . VMware ESX Server can be used in conjunction with a SAN (storage area A SAN is a specialized high-speed network of storage devices and switches. mingnoreftatan.tk Introduction to Storage. Area Networks. Jon Tate. Fabiano Lucchese. Richard Moore. Learn basic SAN terminology and component uses.
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A SAN, or storage area network, is a dedicated network that is separate from LANs data rates (Gigabits/sec) between member storage peripherals and by its . PDF | On Dec 1, , Vladimir Riabov and others published Storage Area Networks Shares of leading companies in the SAN market (Gardner ) . Direct attached storage (DAS), storage area network (SAN), and network attached NAS is the highest layer of storage and can be built on top of a SAN or DAS.
This is an especially useful approach in small and midsize businesses that may not have the funds or expertise to support a Fibre Channel SAN. Organizations use SANs for distributed applications that need fast local network performance. SANs improve the availability of applications through multiple data paths.
They can also improve application performance because they enable IT administrators to offload storage functions and segregate networks.
Additionally, SANs help increase the effectiveness and use of storage because they enable administrators to consolidate resources and deliver tiered storage. SANs also improve data protection and security. Finally, SANs can span multiple sites, which helps companies with their business continuity strategies. A SAN switch's only job is to move storage traffic.
The switch checks the data packet and identifies its origin and destination. Then, the switch directs the packet to the right storage system.
FC switches are meant to be used with high-performance networks. SAN switches can also be Ethernet based.
Organizations can combine many switches to build large SAN fabrics that connect many servers and storage ports. Virtual SANs yield a number of benefits, such as ease of management and scalability.
For the most part, VSANs are hardware-agnostic.
As long as the hypervisor recognizes and supports the storage hardware, the VSAN can use it, although each vendor has its own requirements. Unified SAN Unified SAN is based on the concept of unified storage , which exposes file storage and block storage through a single storage device, usually a modified network-attached storage appliance NAS appliance. A converged SAN uses a common network infrastructure for network and SAN traffic to eliminate redundant infrastructure and to reduce cost and complexity.
Converged SANs are almost always based on 10 Gigabit Ethernet , and multiple network ports are sometimes bonded together to increase throughput. SAN pros and cons The main benefit of using a SAN is that raw storage is treated as a pool of resources that IT can centrally manage and allocate on an as-needed basis.
SANs are also highly scalable because capacity can be added as required.
SAN is generally either high end fibrechannel or can also be iscsi. Got it?
If your asking the differences between DAS- NAS -SAN you are in the data storage context; in this area many technologies exists which share a primary common goal: the persistence and availability of your data. Block devices and filesystems Most storage devices share the same physical and logical structure, in order to be able to locate the data you want, you need a way to identify where your data resides, so this is the reason of why Hard Disk drives have sectors or simply "blocks" , in many cases this reflects the layout of the data written into the physical medium.
But accessing your data by addressing the sector number while not very complex, it's an error prone method and you have to keep track yourself of the data you write and the sectors you have written to.
This explains the difference between a block device and a filesystem, a filesystem must reside on a block device. Hard disk drives need to communicate somehow, and they need to use a well defined physical interface and protocol in order for your computer to understand them, the most common interface and protocol employed today for PC is the S-ATA or Serial ATA or Serial Advanced Technology Attachment.
And unless you access your disk by block numbers you need a file system on top of it in order to put it at good use. NAS But what if you can provide access to your file-system to other computers for transferring files?
What they do is share files over a network, of course file implies an underlying file-system structure and file-system implies block device, but because it's done over a network it's called as NAS - Network Attached Storage.
All of this interfaces explicitly prohibit remote lookups of block addresses for security reasons first and normally such interfaces are not even implemented.