Logical block addressing is a technique that allows a computer to address a hard disk larger than 528 megabytes. A Logical Block Address (LBA) is a 28-bit value that maps to a specific cylinder-head-sector address on the disk. 28 bits allows sufficient variation to specify addresses on a hard disk up to 8.4 gigabytes in data storage capacity.
The term “Logical block addressing” can also be defined as
- An address that defines where data is stored on the hard drive.
- A common scheme used for specifying the location of blocks of data stored on computer storage devices.
- A run-time function of the system BIOS. The BIOS uses LBA for the following commands: read (with and without retries), read verify, read long, write (with and without retries), write verify, write long, read multiple, write multiple, read DMA, write DMA, seek, and format track.