Disk Array Controller - Front-end and Back-end Side

Front-end and Back-end Side

Disk array controller provides front-end interfaces and back-end interfaces.

  • Back-end interface communicates with controlled disks. Hence protocol is usually ATA (a.k.a. PATA; incorrectly called IDE), SATA, SCSI, FC or SAS.
  • Front-end interface communicates with a computer's host adapter (HBA, Host Bus Adapter) and uses:
    • one of ATA, SATA, SCSI, FC; these are popular protocols used by disks, so by using one of them a controller may transparently emulate a disk for a computer
    • somewhat less popular protocol dedicated for a specific solution: FICON/ESCON, iSCSI, HyperSCSI, ATA over Ethernet or InfiniBand

A single controller may use different protocols for back-end and for front-end communication. Many enterprise controllers use FC on front-end and SATA on back-end.

Read more about this topic:  Disk Array Controller

Famous quotes containing the word side:

    As I went forth early on a still and frosty morning, the trees looked like airy creatures of darkness caught napping; on this side huddled together, with their gray hairs streaming, in a secluded valley which the sun had not penetrated; on that, hurrying off in Indian file along some watercourse, while the shrubs and grasses, like elves and fairies of the night, sought to hide their diminished heads in the snow.
    Henry David Thoreau (1817–1862)