Read-ahead is the most common type of read caching. [RW94]
In on-arrival read-ahead caching, upon arriving at the track containing the requested data, the controller reads the entire track into cache rather than reading and sending only the requested sectors. [RW94]
In a second type of read-ahead caching, the drive continues to read from the disk beyond the last requested sector. The drive may or may not stop at the end of the track. [RW94]
The disk cache can be segmented so that unrelated data can be cached at the same time. [RW94]