FREE(1) 							   User Commands							   FREE(1)

NAME

       free - Display amount of free and used memory in the system

SYNOPSIS

       free [options]

DESCRIPTION

       free  displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the ker-
       nel. The information is gathered by parsing /proc/meminfo. The displayed columns are:

       total  Total installed memory (MemTotal and SwapTotal in /proc/meminfo)

       used   Used memory (calculated as total - free - buffers - cache)

       free   Unused memory (MemFree and SwapFree in /proc/meminfo)

       shared Memory used (mostly) by tmpfs (Shmem in /proc/meminfo)

       buffers
	      Memory used by kernel buffers (Buffers in /proc/meminfo)

       cache  Memory used by the page cache and slabs (Cached and SReclaimable in /proc/meminfo)

       buff/cache
	      Sum of buffers and cache

       available
	      Estimation of how much memory is available for starting new applications, without swapping. Unlike the data provided by the cache or
	      free  fields, this field takes into account page cache and also that not all reclaimable memory slabs will be reclaimed due to items
	      being in use (MemAvailable in /proc/meminfo, available on kernels 3.14, emulated on kernels 2.6.27+, otherwise the same as free)

OPTIONS

       -b, --bytes
	      Display the amount of memory in bytes.

       -k, --kibi
	      Display the amount of memory in kibibytes.  This is the default.

       -m, --mebi
	      Display the amount of memory in mebibytes.

       -g, --gibi
	      Display the amount of memory in gibibytes.

       --tebi Display the amount of memory in tebibytes.

       --pebi Display the amount of memory in pebibytes.

       --kilo Display the amount of memory in kilobytes. Implies --si.

       --mega Display the amount of memory in megabytes. Implies --si.

       --giga Display the amount of memory in gigabytes. Implies --si.

       --tera Display the amount of memory in terabytes. Implies --si.

       --peta Display the amount of memory in petabytes. Implies --si.

       -h, --human
	      Show all output fields automatically scaled to shortest three digit unit and display the units of print out.   Following	units  are
	      used.

		B = bytes
		K = kibibyte
		M = mebibyte
		G = gibibyte
		T = tebibyte
		P = pebibyte

	      If unit is missing, and you have exbibyte of RAM or swap, the number is in tebibytes and columns might not be aligned with header.

       -w, --wide
	      Switch  to the wide mode. The wide mode produces lines longer than 80 characters. In this mode buffers and cache are reported in two
	      separate columns.

       -c, --count count
	      Display the result count times.  Requires the -s option.

       -l, --lohi
	      Show detailed low and high memory statistics.

       -s, --seconds delay
	      Continuously display the result delay  seconds apart.  You may actually specify any floating point number for delay using  either  .
	      or , for decimal point.  usleep(3) is used for microsecond resolution delay times.

       --si   Use kilo, mega, giga etc (power of 1000) instead of kibi, mebi, gibi (power of 1024).

       -t, --total
	      Display a line showing the column totals.

       --help Print help.

       -V, --version
	      Display version information.

FILES

       /proc/meminfo
	      memory information

BUGS

       The value for the shared column is not available from kernels before 2.6.32 and is displayed as zero.

       Please send bug reports to
	      <procps@freelists.org>

SEE ALSO

       ps(1), slabtop(1), top(1), vmstat(8).

procps-ng							    2016-06-03								   FREE(1)