A petabyte (derived from the SI prefix peta- is a unit of information or computer storage equal to one quadrillion (one long scale billiard) bytes. It is commonly abbreviated PB.

Because of irregularities in definition and usage of the kilobyte, the exact number in common practice could be either one of the following:

• 1,000,000,000,000,000 bytes - 1000⁵, or 10¹⁵.
• 1,125,899,906,842,624 bytes - 1024⁵, or 2⁵⁰. This capacity maybe expressed unambiguously as a pebibyte.

terabyte << petabyte << exabyte

Petabytes in use

The San Diego Supercomputer Center (SDSC) in the USA has a 1 petabyte hard disk store and a 6 petabyte robotic tape store, both attached to the National Science Foundation's TeraGrid network. (Source: Electronics Weekly, Dec 11, 2002)

The Internet Archive Wayback Machine contains approximately 1 petabyte of data and is currently growing at a rate of 20 terabytes per month. (Source: Internet Archive FAQ)

NOB Cross media facilities in the Netherlands employs a 1.5 petabyte storage network for the storage of all old and new public television and radio content in digital format. Within the next year, most Dutch public television content will be pulled directly out of this database during broadcast.