From LinuxReviews
Jump to navigationJump to search

A zettabyte (derived from the SI prefix zetta-) is a unit of information or computer storage equal to one sextillion (one long scale trilliard) bytes. It is commonly abbreviated ZB. At this time, no computer has one zettabyte of storage. Because of a traditional inconsistency, "zettabytes" are often intended to mean zebibytes in common speech. This usage is not recommended as it creates confusion (see below) and has been facing increasing opposition by many technical standards and legal entities in the past few years.

Quantities of bytes
Value Metric Linux
1000 kB kilobyte KB
10002 MB megabyte MB
10003 GB gigabyte GB
10004 TB terabyte TB
10005 PB petabyte PB
10006 EB exabyte EB
10007 ZB zettabyte ZB
10008 YB yottabyte YB
Binary prefix
Value IEC 80000-13 JEDEC Linux
1024 KiB kibibyte KB kilobyte K KiB
10242 MiB mebibyte MB megabyte M MiB
10243 GiB gibibyte GB gigabyte G GiB
10244 TiB tebibyte T TiB
10245 PiB pebibyte P PiB
10246 EiB exbibyte E EiB
10247 ZiB zebibyte Z ZiB
10248 YiB yobibyte Y YiB


Because of irregularities in the definition and usage of terms for byte multiples, the exact number can be either one of the following:

  • 1,000,000,000,000,000,000,000 bytes — 10007, or 1021.
  • 1,180,591,620,717,411,303,424 bytes — 10247, or 270.

Because of these irregularities, the term "zebibyte" has been proposed as an unambiguous reference to the latter value.

The Z in Sun's ZFS file system originally stood for zettabyte.