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