The exabyte is a multiple of the unit byte for digital information. The prefix exa indicates
multiplication by the sixth power of 1000 or 1018 in the International System of Units.
Therefore one exabyte is one quintillion bytes. 1 EB = 10006bytes = 1018bytes = 1000000000000000000B
= 1000petabytes = 1millionterabytes = 1billiongigabytes. A
related unit, the exbibyte, using a binary prefix, is 10246bytes, about 15% larger.
Usage examples In principle, the 64-bit microprocessors found
in many computers can address 16 exabytes of memory.
The world's technological capacity to store information grew from 2.6 exabytes in 1986
to 15.8 in 1993, over 54.5 in 2000, and to 295 exabytes in 2007. This is equivalent to
less than one CD per person in 1986, roughly 4 CDs per person of 1993, 12 CDs per person
in the year 2000, and almost 61 CDs per person in 2007. Piling up the imagined 404 billion
CDs from 2007 would create a stack from the earth to the moon and a quarter of this distance
beyond. The world’s technological capacity to receive
information through one-way broadcast networks was 432 exabytes of information in 1986, 715
exabytes in 1993, 1,200 exabytes in 2000, and 1,900 in 2007.
The world's effective capacity to exchange information through two-way telecommunication
networks was 0.281 exabytes of information in 1986, 0.471 in 1993, 2.2 in 2000, and 65
exabytes in 2007. In 2004, the global monthly Internet traffic
passed 1 exabyte for the first time. In January 2007, Bret Swanson of the Discovery Institute
coined the term exaflood for a supposedly impending flood of exabytes that would cause
the Internet's congestive collapse. Nevertheless, the global Internet traffic has continued
its exponential growth, undisturbed, and as of March 2010 it is estimated at 21 exabytes
per month. According to the June 2009 Cisco Visual Networking
Index IP traffic forecast, global mobile data traffic will grow at a CAGR of 131 percent
between 2008 and 2013, reaching over two exabytes per month by 2013.
According to the 2011 update of Cisco's VNI IP traffic forecast, by 2015, annual global
IP traffic will reach 966 exabytes or nearly one full zettabyte. Internet video will account
for 61% of total Internet data. According to the February 2013 update of Cisco
VNI Forecast for 2012–17, annual global IP traffic will pass the zettabyte threshold
by the end of 2016. In 2016 global IP traffic will reach 1.3 zettabytes per year or 110.3
exabytes per month. By 2017 global mobile data traffic will reach 11.2 exabytes per
month; growing 13-fold from 2012 to 2017. The global data volume at the end of 2009
had reached 800 exabytes. According to an IDC paper sponsored by EMC
Corporation, 161 exabytes of data were created in 2006, "3 million times the amount of information
contained in all the books ever written", with the number expected to hit 988 exabytes
in 2010. According to the CSIRO, in the next decade,
astronomers expect to be processing 10 petabytes of data every hour from the Square Kilometre
Array telescope. The array is thus expected to generate approximately one exabyte every
four days of operation. According to IBM, the new SKA telescope initiative will generate
over an exabyte of data every day. IBM is designing hardware to process this information.
According to the Digital Britain Report, 494 exabytes of data was transferred across the
globe on June 15, 2009. Several filesystems use disk formats that
support theoretical volume sizes of several exabytes, including Btrfs, XFS, ZFS, exFAT,
NTFS, HFS Plus, and ReFS. The ext4 file system format supports volumes
up to 1 exabyte in size, although the userspace tools cannot yet administer such filesystems.
Oracle Corporation claimed the first exabyte tape library with the SL8500 and the T10000C
tape drive in January 2011. Practical comparisons
All words ever spoken A popular expression claims that "all words
ever spoken by human beings" could be stored in approximately 5 exabytes of data, often
citing a project at the UC Berkeley School of Information in support. The 2003 University
of California Berkeley report credits the estimate to the website of Caltech researcher
Roy Williams, where the statement can be found as early as May 1999. This statement has been
criticized. Mark Liberman calculated the storage requirements for all human speech at 42 zettabytes,
if digitized as 16 kHz 16-bit audio, although he did freely confess that "maybe the authors
[of the exabyte estimate] were thinking about text".
Earlier studies from the University of California, Berkeley, estimated that by the end of 1999,
the sum of human-produced information was about 12 exabytes of data. The 2003 Berkeley
report stated that in 2002 alone, "telephone calls worldwide on both landlines and mobile
phones contained 17.3 exabytes of new information if stored in digital form" and that "it would
take 9.25 exabytes of storage to hold all U.S. [telephone] calls each year". International
Data Corporation estimates that approximately 160 exabytes of digital information were created,
captured, and replicated worldwide in 2006. Research from University of Southern California
estimates that the amount of data stored in the world by 2007 was 295 exabytes and the
amount of information shared on two-way communications technology, such as cell phones in 2007 as
65 exabytes. 100,000 Libraries of Congress
The content of Library of Congress is commonly estimated to hold 10 terabytes of data in
all printed material. Recent estimates of the size including audio, video, and digital
materials is from 3 petabytes to 20 petabytes. Therefore, one exabyte could hold a hundred
thousand times the printed material, or 500 to 3,000 times all content of the Library
of Congress. Google
In 2013, Randall Munroe compiled published facts about Google's data centers, and estimated
that the company has about 10 exabytes stored on disk plus about 5 exabytes on tape backup.
The company's response to Munroe's estimate was "No comment."
See also Binary prefix
Orders of magnitude References
External links exabyte