RAIN
RAID Recovery - RAIN
Redundant/Reliable Array of Inexpensive/Independent Nodes or RAIN is a type of computer storage. RAIN is advancement over Raid and the former is an open architecture approach to computer storage. In open architecture, commodity or low cost computing hardware and high end and intelligent management software are brought together or combined so that it can exceed the reliability and availability qualities of the high end and expensive storage systems.
Unlike Raid that relies on drive controllers or operating system device drivers, RAIN provides data reliability by relying on software to organize multiple separate computer server. In Raid copies of a particular data are stored on separate multiple hard drives on a server whereas in RAIN data is replicated to multiple servers. In RAIN the responsibility of the software is that it manages the cluster of RAIN servers and it is aware of the location of each of the copies and whenever there is any server failure, it makes necessary amount of additional copies so that the required level of redundancy is maintained. The data storage and protection systems that RAIN offers are more distributed, shareable, and scalable.
Standard IP based LANs, metropolitan-area networks (MAN) and/or WANs are used to physically interconnect the RAIN nodes. By this administrators can create an integrated storage and protection grid of RAIN nodes across multiple data centers. RAIN nodes are enabled to protect local data while at the same time offering offsite protection for the data created at other data centers with it has MAN and WAN connectivity. The RAIN nodes provide 1 terabyte of serial ATA disk storage capacity, standard Ethernet networking and CPU processing power in order to run RAIN and data management software. The RAIN nodes are hardware components and are 1U servers. Instead of storing the data in a single storage sub system, it is reliably stored and protected among the multiple RAIN nodes that are facilitated with own redundant power, cooling, and hot swap disk-drive hardware.
The other very important advantage that RAIN has is that it can be used with tasks that require many instructions per second to be processed. Collections of inexpensive RAIN nodes are assembled instead of using the tightly coupled computing cluster with specialized hardware. The tasks to the various computers are transmitted by the software and when there is a failure the task is retried until and unless a node responds. The RAIN strategy is also used in many of the distributed computing projects.
The distributed file sharing services like Gnutella and eDonkey are fairly similar to RAIN but they do not provide the sufficient redundancy by design. What this means is that if none of the sharing users online have a copy of some part of the file, the file becomes inaccessible. The better basis for implementing such a service is distributed hash table.
