pcp-free - report on free and used memory in the system
pcp [
pcp options]
free [
-bkmgroltVw?] [
-c count] [
-s interval]
pcp-free gives a summary display of the total amount of free and used
physical memory and swap in the system, as well as the caches used by the
kernel.
When invoked via the
pcp(1) command, the
-h/
--host,
-a/
--archive,
-O/
--origin,
-s/
--samples,
-t/
--interval,
-Z/
--timezone and several other
pcp options become
indirectly available, see
PCPIntro(1) for their descriptions.
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).
The available command line options are:
-
-b, --bytes
- Display the amount of memory in bytes.
-
-c count, --samples=count,
--count= count
- Terminate the display after count iterations. See
also -s.
-
-g, --gigabytes
- Display the amount of memory in gigabytes.
-
-k, --kilobytes
- Display the amount of memory in kilobytes. This is the
default.
-
-l, --lohi
- Display detailed low and high memory statistics.
-
-m, --megabytes
- Display the amount of memory in megabytes.
- -o
- Disable the display of a "buffer adjusted" line.
If the -o option is not specified, free subtracts buffer
memory from the used memory and adds it to the free memory reported.
-
-r, --terabytes
- Display the amount of memory in terabytes.
-
-s delay, --interval=delay,
--seconds= delay
- Activate continuous polling delay seconds apart. You
may specify any floating point number for delay, or indeed any
valid pmParseInterval(3) specification, which includes microsecond
resolution delay times. This can be used in conjunction with the -c
option.
-
-t, --total
- Display a line containing the totals.
-
-V, --version
- Display version number and exit.
-
-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.
-
-?, --help
- Display usage message and exit.
pcp-free is inspired by the
free(1) command and aims to be command
line and output compatible with it.
Environment variables with the prefix
PCP_ are used to parameterize the
file and directory names used by PCP. On each installation, the file
/etc/pcp.conf contains the local values for these variables. The
$PCP_CONF variable may be used to specify an alternative configuration
file, as described in
pcp.conf(5).
For environment variables affecting PCP tools, see
pmGetOptions(3).
PCPIntro(1),
pcp(1),
free(1),
pmParseInterval(3) and
environ(7).