Ubuntu Manpage: pcp-vmstat, pmstat - high-level system performance overview

NAME

       pcp-vmstat, pmstat - high-level system performance overview

SYNOPSIS

       pcp [pcp options] vmstat [interval [samples]]

       pmstat  [-gLlPxz?]   [-a  archive] [-A align] [-h host] [-H file] [-n pmnsfile] [-O offset] [-p port] [-s
       samples] [-S starttime] [-t interval] [-T endtime] [-Z timezone]

DESCRIPTION

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 standalone 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
log 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.

Standalone 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 as a ``slave'' 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 slave 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.

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 log 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 slave of a new pmtime(1) 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.

-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 1 second. 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.

-x, --xcpu
The extended CPU metrics option, causes two additional CPU metrics to be reported, namely wait for
I/O ("wa") and virtualisation steal time ("st").

-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).

OUTPUT

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.

DIAGNOSTICS

       All are generated on standard error and are intended to be self-explanatory.

FILES

       $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

PCP ENVIRONMENT

       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).

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

OUTPUT

DIAGNOSTICS

FILES

PCP ENVIRONMENT

SEE ALSO