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 mem‐
       ory in the system, as well as the buffers and caches used by  the  ker‐
       nel.  The  information  is  gathered by parsing /proc/meminfo. The dis‐
       played 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, available
              on kernels 2.6.32, displayed as zero if not available)

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

       cache  Memory  used  by  the  page  cache and slabs (Cached and Slab 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, avail‐
              able 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, kilo
              Display the amount of memory in kilobytes.  This is the default.

       -m, mega
              Display the amount of memory in megabytes.

       -g, giga
              Display the amount of memory in gigabytes.

       tera Display the amount of memory in terabytes.

       peta Display the amount of memory in petabytes.

       -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 = kilos
                M = megas
                G = gigas
                T = teras
                P = petas

              If unit is missing, and you have exabyte of  RAM  or  swap,  the
              number  is  in  terabytes  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 seconds
              Continuously display the result delay seconds  apart.   You  may
              actually  specify any floating point number for delay, usleep(3)
              is used for microsecond resolution delay times.

       si   Use power of 1000 not 1024.

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

       help Print help.

       -V, version
              Display version information.

FILES
       /proc/meminfo
              memory information

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

AUTHORS
       Written by Brian Edmonds.

REPORTING BUGS
       Please send bug reports to ⟨procps@freelists.org⟩



procps-ng                          July 2014                           FREE(1)