Zettabyte

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
Decimal 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

Size

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.