Buffering - A buffer is an in-memory buffer that contains a cache of disk blocks.
Read-ahead - looks at blocks ahead in anticipation in case the querier asks for subsequent blocks.
Disk-Arm Scheduling - the algorithm reorders the block requests so as to optimise the speed of queries as a whole, via the elevator algorithm.
File Oragnisation - involves allocating blocks of a file contiguously as much as possible. Sometimes files are fragmented. To deal with this, some systmes have defragmentation utilities.