lsmem
(1)list the ranges of available memory with their online status
Options
13-a--allList each individual memory block, instead of combining memory blocks with similar attributes.
-b--bytesPrint the sizes in bytes rather than in a human-readable format. By default, the unit, sizes are expressed in, is byte, and unit prefixes are in power of 2^10 (1024). Abbreviations of symbols are exhibited truncated in order to reach a better readability, by exhibiting alone the first letter of them; examples: "1 KiB" and "1 MiB" are respectively exhibited as "1 K" and "1 M", then omitting on purpose the mention "iB", which is part of these abbreviations.
-J--jsonUse JSON output format.
-n--noheadingsDo not print a header line.
-o--outputlistSpecify 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-allOutput all available columns.
-P--pairsProduce output in the form of key="value" pairs. All potentially unsafe value characters are hex-escaped (\x<code>).
-r--rawProduce output in raw format. All potentially unsafe characters are hex-escaped (\x<code>).
-S--splitlistSpecify which columns (attributes) use to split memory blocks to ranges. The supported columns are STATE, REMOVABLE, NODE and ZONES, or "none". The other columns are silently ignored. For more details see DESCRIPTION above.
-s--sysrootdirectoryGather 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.
--summarywhenThis 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.
-h--helpDisplay help text and exit.
-V--versionDisplay version and exit.
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 is 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.
AUTHORS
REPORTING BUGS
For bug reports, use the issue tracker https://github.com/util-linux/util-linux/issues.
AVAILABILITY
The lsmem command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.