NAME

       lsmem - list the ranges of available memory with their online status

SYNOPSIS

       lsmem [options]

DESCRIPTION

       The lsmem command lists the ranges of available memory with their online status. The listed memory blocks
       correspond to the memory block representation in sysfs. The command also shows the memory block size  and
       the amount of memory in online and offline state.

       The default output compatible with original implementation from s390-tools, but it's strongly recommended
       to avoid using default outputs in your scripts.  Always explicitly define expected columns by  using  the
       --output option together with a columns list in environments where a stable output is required.

       The  lsmem  command  lists  a  new memory range always when the current memory block distinguish from the
       previous block by some output column.  This default behavior is  possible  to  override  by  the  --split
       option (e.g. lsmem --split=ZONES).  The special word "none" may be used to ignore all differences between
       memory blocks and to create as large as possible continuous ranges.  The opposite semantic  is  --all  to
       list individual memory blocks.

       Note that some output columns may provide inaccurate information if a split policy forces lsmem to ignore
       differences in some attributes. For example if you merge removable and non-removable memory blocks to the
       one range than all the range will be marked as non-removable on lsmem output.

       Not  all  columns  are supported on all systems.  If an unsupported column is specified, lsmem prints the
       column but does not provide any data for it.

       Use the --help option to see the columns description.

OPTIONS

       -a, --all
              List each individual memory block, instead of combining memory blocks with similar attributes.

       -b, --bytes
              Print the SIZE column in bytes rather than in a human-readable format.

       -h, --help
              Display help text and exit.

       -J, --json
              Use JSON output format.

       -n, --noheadings
              Do not print a header line.

       -o, --output list
              Specify which output columns to print.  Use --help to get a list of all  supported  columns.   The
              default  list  of  columns may be extended if list is specified in the format +list (e.g. lsmem -o
              +NODE).

       --output-all
              Output all available columns.

       -P, --pairs
              Produce output in the form of key="value" pairs.   All  potentially  unsafe  characters  are  hex-
              escaped (\x<code>).

       -r, --raw
              Produce output in raw format.  All potentially unsafe characters are hex-escaped (\x<code>).

       -S, --split list
              Specify  which  columns  (attributes) use to split memory blocks to ranges.  The supported columns
              are STATE, REMOVABLE, NODE and ZONES, or "none". The another columns  are  silently  ignored.  For
              more details see DESCRIPTION above.

       -s, --sysroot directory
              Gather  memory  data  for a Linux instance other than the instance from which the lsmem command is
              issued.  The specified directory is the system root of the Linux instance to be inspected.

       -V, --version
              Display version information and exit.

       --summary[=when]
              This option controls summary lines output.  The optional argument when can  be  never,  always  or
              only.   If  the  when argument is omitted, it defaults to "only". The summary output is suppressed
              for --raw, --pairs and --json.

AUTHOR

       lsmem was originally written by Gerald Schaefer for s390-tools in Perl. The C version for util-linux  was
       written by Clemens von Mann, Heiko Carstens and Karel Zak.

SEE ALSO

       chmem(8)

AVAILABILITY

       The  lsmem command is part of the util-linux package and is available from Linux Kernel Archive ⟨https://
       www.kernel.org/pub/linux/utils/util-linux/⟩.