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units(7) [suse man page]

UNITS(7)						     Linux Programmer's Manual							  UNITS(7)

NAME

       units, kilo, kibi, mega, mebi, giga, gibi - decimal and binary prefixes

DESCRIPTION

   Decimal prefixes
       The  SI	system	of units uses prefixes that indicate powers of ten.  A kilometer is 1000 meter, and a megawatt is 1000000 watt.  Below the
       standard prefixes.

	      Prefix   Name    Value
	      y        yocto   10^-24 = 0.000000000000000000000001
	      z        zepto   10^-21 = 0.000000000000000000001
	      a        atto    10^-18 = 0.000000000000000001
	      f        femto   10^-15 = 0.000000000000001
	      p        pico    10^-12 = 0.000000000001
	      n        nano    10^-9  = 0.000000001
	      u        micro   10^-6  = 0.000001
	      m        milli   10^-3  = 0.001
	      c        centi   10^-2  = 0.01
	      d        deci    10^-1  = 0.1
	      da       deka    10^ 1  = 10
	      h        hecto   10^ 2  = 100
	      k        kilo    10^ 3  = 1000
	      M        mega    10^ 6  = 1000000
	      G        giga    10^ 9  = 1000000000
	      T        tera    10^12  = 1000000000000
	      P        peta    10^15  = 1000000000000000
	      E        exa     10^18  = 1000000000000000000
	      Z        zetta   10^21  = 1000000000000000000000
	      Y        yotta   10^24  = 1000000000000000000000000

       The symbol for micro is the Greek letter mu, often written u in an ASCII context where this Greek letter is not available.  See also

	      http://physics.nist.gov/cuu/Units/prefixes.html

   Binary prefixes
       The binary prefixes resemble the decimal ones, but have an additional 'i' (and "Ki" starts with a capital 'K').	The names  are	formed	by
       taking the first syllable of the names of the decimal prefix with roughly the same size, followed by "bi" for "binary".

	      Prefix   Name   Value
	      Ki       kibi   2^10 = 1024
	      Mi       mebi   2^20 = 1048576
	      Gi       gibi   2^30 = 1073741824
	      Ti       tebi   2^40 = 1099511627776
	      Pi       pebi   2^50 = 1125899906842624
	      Ei       exbi   2^60 = 1152921504606846976

       See also

	      http://physics.nist.gov/cuu/Units/binary.html

   Discussion
       Before these binary prefixes were introduced, it was fairly common to use k=1000 and K=1024, just like b=bit, B=byte.  Unfortunately, the M
       is capital already, and cannot be capitalized to indicate binary-ness.

       At first that didn't matter too much, since memory modules and disks came in sizes that were powers of two, so everyone knew that  in  such
       contexts "kilobyte" and "megabyte" meant 1024 and 1048576 bytes, respectively.  What originally was a sloppy use of the prefixes "kilo" and
       "mega" started to become regarded as the "real true meaning" when computers were involved.  But then  disk  technology  changed,  and  disk
       sizes  became  arbitrary  numbers.   After  a period of uncertainty all disk manufacturers settled on the standard, namely k=1000, M=1000k,
       G=1000M.

       The situation was messy: in the 14k4 modems, k=1000; in the 1.44MB diskettes, M=1024000; etc.  In 1998 the IEC approved the  standard  that
       defines the binary prefixes given above, enabling people to be precise and unambiguous.

       Thus, today, MB = 1000000B and MiB = 1048576B.

       In the free software world programs are slowly being changed to conform.  When the Linux kernel boots and says

	      hda: 120064896 sectors (61473 MB) w/2048KiB Cache

       the MB are megabytes and the KiB are kibibytes.

COLOPHON

       This  page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2001-12-22								  UNITS(7)

Check Out this Related Man Page

CFDISK(8)							 GNU cfdisk Manual							 CFDISK(8)

NAME

       GNU cfdisk - a curses-based partition table manipulation program

SYNOPSIS

       cfdisk [options] [device]

DESCRIPTION

       cfdisk  is  a  disk  partition  manipulation program, which allows you to create, destroy, resize, move and copy partitions on a hard drive
       using a simple menu-driven interface. It is useful for organising the disk space on a new drive, reorganising an old drive, creating  space
       for  new operating systems, and copying data to new hard disks. For a list of the supported partition types, see the --list-partition-types
       option below.

OPTIONS

       -h, --help
	      displays a help message.

       -v, --version
	      displays the program's version.

       -a, --arrow-cursor
	      use an arrow cursor, instead of reverse video highlighting, in case your terminal doesn't support it.

       -z, --new-table
	      create a new partition table on the disk. This is useful if you want to change the partition table type or want to  repartition  you
	      entire drive. Note that this does not delete the old table on the disk until you commit the changes.

       -u, --units=UNIT
	      sets the default display units to UNIT. A list of possible units is given below.

       -t, --list-partition-types
	      displays a list of supported partition types and features.

UNITS

       You can choose in what unit cfdisk should display quantities like partition sizes. You can choose from sectors, percents, bytes, kilobytes,
       etc. Note that one kilobyte is equal to 1,000 bytes, as this is consistent with the SI prefixes and is used by hard disk manufacturers.	If
       you  prefer  to	see  the sizes in units with binary prefixes, you should instead select one kilo binary byte (kibibyte), which is equal to
       1,024 bytes. Whatever display unit you have chosen, you can always enter the quantities in the unit of your choice, for example 1000000B or
       1000kB.

       compact
	      display each size in the most suitable unit from B, kB, MB, GB and TB.

       B      one byte

       kB     one kilobyte (1,000 bytes)

       MB     one megabyte (1,000,000 bytes)

       GB     one gigabyte (1,000,000,000 bytes)

       TB     one terabyte (1,000,000,000,000 bytes)

       KiB    one kilo binary byte (1,024 bytes)

       MiB    one mega binary byte (1,048,576 bytes)

       GiB    one giga binary byte (1,073,741,824 bytes)

       TiB    one tera binary byte (1,099,511,627,776 bytes)

       s      one sector. It depends on the sector size of the disk. You can use it if you want to see or choose the exact size in sectors.

       %      one percent from the size of the disk

       cyl    one cylinder. It depends on the cylinder size.

       chs    use CHS display units.

BUGS

       There are no known bugs. We are in early stages for development, so be careful.

SEE ALSO

       fdisk(8), mkfs(8), parted(8) The cfdisk program is fully documented in the info(1) format GNU cfdisk User Manual manual.

fdisk								   16 June, 2006							 CFDISK(8)
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