Managing RAID on Linux

The AT Attachment (ATA) and Integrated Disk Electronics (IDE)

Integrated disk electronics, or IDE, has had many incarnations and many names since its introduction in 1986. Originally, hard drives were small enough, in both size and capacity, to fit directly onto disk controllers. As storage requirements grew, manufacturers realized that housing drives on controller cards was an inefficient use of space. Soon drives and controllers became separate entities, connected by ribbon cable. This meant that drives could grow in size without interfering with the expandability of the motherboard. It was common for these integrated controller cards to make adjacent slots on the motherboard inaccessible. Manufacturers eventually decided that portions of the controller could be housed directly on the drives and that creating a standard drive interface would allow for both expandability and portability. Originally called IDE in several proprietary implementations, a standardized version called the AT Attachment, or ATA, was eventually ratified (although many people still use the terms IDE and ATA interchangeably). This new disk interface was called the AT Attachment because it was introduced with the ISA (AT) motherboard. It quickly grew in popularity, and today the ATA interface is the most widely deployed consumer disk interface. Figure 2-20 shows the ATA interface.

Figure 2-20. The ATA interface ...