RAID controller
RAID Recovery - RAID controller
A disk array controller is a device made of multiple disk array control units that implements the data read/write operation. Each of this unit has channel IF units, disk IF units, cache memory units and shared memory units. Moreover, the disk array controller includes inter connection for interconnecting shared memory units and the cache memory units across the border of the disk array control units. Thus, helping increase the data transfer performance which usually deteriorates due to distribution of data between the disk array control units. It happens because multiple disk array control units act as a single disk array controller.
A disk array controller manages the physical drive drives and presents them as logical unites to the computer. Almost always it implements hardware RAID, this is the reason it is also considered as RAID controller. It can also provide additional disk cache.
Disk array controller provides front-end interfaces and back-end interfaces.
Front-end interface connects with controller disks. Here, protocols are ATA, SATA, SCSI, FC, and SAS.
Back-end-interface connects with host adapter of computer. Its uses are:
1. The commonly used protocols ATA, SATA, SCSI, and FC are used by disks, so a controller, by using one of them, may lucidly emulate a disk for a computer.
2. Some rarely used protocol devoted for a particular solution like FICON/ESCON, iSCSI, HyperSCSI, InfiniBand, and ATA over Ethernet.
Single disk controller also can use various protocols for back-end as well as front end communication. In recent times, many enterprise controller have chosen SATA on back-end and FC on front-end.
