NAME
pmstat - high-level system performance overview
SYNOPSIS
pmstat [-Llpz] [-A align] [-a archive] [-h host] [-H file]
[-n pmnsfile] [-O offset] [-S starttime] [-s samples] [-T
endtime] [-t interval] [-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.
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 an archive).
The -t option may be used to change the default reporting
interval. 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).
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 the local host
using the standalone PM_CONTEXT_LOCAL variant of pmNewCon
text(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 sup
plying multiple -h flags.
Alternatively, if the -a option is used, the metrics are
retrieved from the Performance Co-Pilot archive log files
identified by the base name archive. Multiple 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
an archive implies a host name, and nominating a host pre
cludes using an archive, so the options -L, -a and -h are
mutually exclusive.
Normally pmstat operates on the default Performance Met
rics Name Space (PMNS), however if the -n option is
pmnsfile.
If the -s the option is specified, samples defines the
number of samples to be retrieved and reported. If sam
ples is 0 or -s is not specified, pmstat will sample and
report continuously - this is the default behavior.
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 -l option 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).
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 inter
val, in Kbytes. The cache column indicates
average cached memory in use during the inter
val, in Kbytes.
swap The si and so indicate the average rate (per
second) of page swap in and out (respectfully)
during the interval. It is normal for si to be
non-zero, but the system is suffering memory
stress if so is non-zero.
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 transfered.
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.
cpu Percentage of CPU time spent executing user and
processing code (sys), idle loop (idl).
If any values for the associated performance metrics are
unavailable, the value appears as ``?'' in the output.
By default, pmstat 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(5).
The -z option changes the 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.
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(4).
SEE ALSO
PCPIntro(1), pmclient(1), PMAPI(3), pmNewContext(3),
pcp.conf(4) and pcp.env(4).
DIAGNOSTICS
All are generated on standard error, and are intended to
be self-explanatory.
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