What is Logical Block Addressing (LBA)?

Logical Block Address (LBA)

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

  1. An address that defines where data is stored on the hard drive.
  2. A common scheme used for specifying the location of blocks of data stored on computer storage devices.
  3. 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.