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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OUTPUT | FILES | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
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PMSTAT(1) General Commands Manual PMSTAT(1)
pcp-vmstat, pmstat - high-level system performance overview
pcp [pcp options] vmstat [interval [samples]]
pmstat [-gLlPVxz?] [-a archive] [-A align] [-h host] [-H file]
[-n pmnsfile] [-O offset] [-p port] [-s samples] [-S starttime]
[-t interval] [-T endtime] [-Z timezone]
pcp-vmstat ...
pmstat provides a one line summary of system performance every
interval unit of time (the default is 5 seconds). pmstat is
intended to monitor system performance at the highest level, after
which other tools may be used to examine subsystems in which
potential performance problems may be observed in greater detail.
pcp-vmstat is a simple wrapper for use with the pcp(1) command,
providing a more familiar command line format for some users. It
also enables the extended reporting option by default, see the -x
option below.
Multiple hosts may be monitored by supplying more than one host
with multiple -h flags (for live monitoring) or by providing a
name of the hostlist file, where each line contain one host name,
with -H, or multiple -a flags (for retrospective monitoring from
sets of archives).
By default, pmstat fetches metrics by connecting to the
Performance Metrics Collector Daemon (PMCD) on the local host. If
the -L option is specified, then pmcd(1) is bypassed, and metrics
are fetched from PMDAs on the local host using the stand-alone
PM_CONTEXT_LOCAL variant of pmNewContext(3). When the -h option
is specified, pmstat connects to the pmcd(1) on host and fetches
metrics from there. As mentioned above, multiple hosts may be
monitored by supplying multiple -h flags.
Alternatively, if the -a option is used, the metrics are retrieved
from the Performance Co-Pilot archive files identified by archive,
which is a comma-separated list of names, each of which may be the
base name of an archive or the name of a directory containing one
or more archives. Multiple sets of archives may be replayed by
supplying multiple -a flags. When the -a flag is used, the -P
flag may also be used to pause the output after each interval.
Stand-alone mode can only connect to the local host, using a set
of archives implies a host name, and nominating a host precludes
using an archive, so the options -L, -a and -h are mutually
exclusive.
pmstat may relinquish its own timing control, and operate under
the control of a pmtime(1) process that uses a GUI dialog to
provide timing control. In this case, either the -g option should
be used to start pmstat as the sole client of a new pmtime(1)
instance, or -p should be used to attach pmstat to an existing
pmtime(1) instance via the IPC channel identified by the port
argument.
The -S, -T, -O and -A options may be used to define a time window
to restrict the samples retrieved, set an initial origin within
the time window, or specify a ``natural'' alignment of the sample
times; refer to PCPIntro(1) for a complete description of these
options.
The available command line options are:
-a archive, --archive=archive
Performance metric values are retrieved from the set of
Performance Co-Pilot (PCP) archive files identified by the
archive argument, which is a comma-separated list of names,
each of which may be the base name of an archive or the name
of a directory containing one or more archives.
-A align, --align=align
Force the initial sample to be aligned on the boundary of a
natural time unit align. Refer to PCPIntro(1) for a complete
description of the syntax for align.
-g, --guimode
Start pmstat as the client of a new pmtime(1) server process
for replay of archived performance data using the pmtime(1)
graphical user interface.
-h host, --host=host
Fetch performance metrics from pmcd(1) on host, rather than
from the default localhost.
-H path, --hostsfile=path
Specify the path to a file containing a set of hostnames
where pmcd(1) is running , rather than using the default
localhost.
-K spec, --spec-local=spec
When fetching metrics from a local context (see -L), the -K
option may be used to control the DSO PMDAs that should be
made accessible. The spec argument conforms to the syntax
described in pmSpecLocalPMDA(3). More than one -K option may
be used.
-l, --suffix
Prints the last 7 characters of a hostname in summaries
involving more than one host (when more than one -h option
has been specified on the command line).
-L, --local-PMDA
Use a local context to collect metrics from DSO PMDAs on the
local host without PMCD. See also -K.
-n pmnsfile, --namespace=pmnsfile
Load an alternative Performance Metrics Name Space (PMNS(5))
from the file pmnsfile.
-O origin, --origin=origin
When reporting archived metrics, start reporting at origin
within the time window (see -S and -T). Refer to PCPIntro(1)
for a complete description of the syntax for origin.
-p port, --guiport=port
Attach pmstat to an existing pmtime(1) time control process
instance via the IPC channel identified by the port argument.
This option is normally only used by other tools, e.g.
pmchart(1), when they launch pmstat with synchronized time
control.
-P, --pause
Pause between updates for archive replay.
-s samples, --samples=samples
The samples option defines the number of samples to be
retrieved and reported. If samples is 0 or -s is not
specified, pmstat will sample and report continuously - this
is the default behavior.
-S starttime, --start=starttime
When reporting archived metrics, the report will be
restricted to those records logged at or after starttime.
Refer to PCPIntro(1) for a complete description of the syntax
for starttime.
-t interval, --interval=interval
Set the reporting interval to something other than the
default 5 seconds. The interval argument follows the syntax
described in PCPIntro(1), and in the simplest form may be an
unsigned integer (the implied units in this case are
seconds).
-T endtime, --finish=endtime
When reporting archived metrics, the report will be
restricted to those records logged before or at endtime.
-V, --version
Display version number and exit.
-x, --xcpu
The extended CPU metrics option, causes three additional CPU
metrics to be reported, namely wait for I/O ("wa"),
virtualisation steal time ("st"), and virtual guest time
("gu").
-z, --hostzone
Change the reporting timezone to the local timezone at the
host that is the source of the performance metrics, as
identified via either the -h or -a options.
-Z timezone, --timezone=timezone
By default, pmtime reports the time of day according to the
local timezone on the system where pmstat is run. The -Z
option changes the timezone to timezone in the format of the
environment variable TZ as described in environ(7).
-?, --help
Display usage message and exit.
The output from pmstat is directed to standard output, and the
columns in the report are interpreted as follows:
loadavg
The 1 minute load average.
memory The swpd column indicates average swap space used during
the interval, in Kbytes. The free column indicates average
free memory during the interval, in Kbytes. The buff
column indicates average buffer memory in use during the
interval, in Kbytes. The cache column indicates average
cached memory in use during the interval, in Kbytes.
If the values become large, they are reported as Mbytes (m
suffix) or Gbytes (g suffix).
swap The metrics in this area of the kernel instrumentation are
of varying value. We try to report the average number of
pages that are paged in (pi) and out (po) per second during
the interval. If the corresponding page swapping metrics
are unavailable, we report the average rate per second of
swap operations in (si) and out (so) during the interval.
It is normal for the ``in'' values to be non-zero, but the
system is suffering memory stress if the ``out'' values are
non-zero over an extended period.
If the values become large, they are reported as thousands
of operations per second (K suffix) or millions of
operations per second (M suffix).
io The bi and bo columns indicate the average rate per second
of block input and block output operations (respectfully)
during the interval. Unless all file systems have a 1
Kbyte block size, these rates do not directly indicate
Kbytes transferred.
If the values become large, they are reported as thousands
of operations per second (K suffix) or millions of
operations per second (M suffix).
system Interrupt rate (in) and context switch rate (cs). Rates
are expressed as average operations per second during the
interval. Note that the interrupt rate is normally at
least HZ (the clock interrupt rate, usually 100) interrupts
per second.
If the values become large, they are reported as thousands
of operations per second (K suffix) or millions of
operations per second (M suffix).
cpu Percentage of CPU time spent executing user and "nice user"
code (us), system and interrupt processing code (sy), idle
loop (id).
If any values for the associated performance metrics are
unavailable, the value appears as ``?'' in the output.
$PCP_VAR_DIR/pmns/*
default PMNS specification files
$PCP_VAR_DIR/config/pmlogger/config.pmstat
pmlogger(1) configuration for creating an archive suitable
for replay with pmstat
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), pmclient(1), pmtime(1), PMAPI(3), pmNewContext(3),
pcp.conf(5), pcp.env(5) and PMNS(5).
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to pcp@groups.io. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2025-02-02.
(At that time, the date of the most recent commit that was found
in the repository was 2025-01-30.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Performance Co-Pilot PCP PMSTAT(1)
Pages that refer to this page: pcpintro(1), pmcd(1), pmclient(1), pmrep(1), pmtime(1), pmgetoptions(3)
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HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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