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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 kernel. 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, 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/mem‐
              info, 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, --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.

       -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

       -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  num‐
              ber 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 ⟨[email protected]⟩



procps-ng                                             July 2014                                               FREE(1)