NAMEpmkstat - high-level system performance overview
SYNOPSISpmkstat [-A align] [-a archive] [-d] [-h host] [-L] [-n pmnsfile] [-O
offset] [-S starttime] [-s samples] [-T endtime] [-t interval] [-Z
timezone] [-z]
DESCRIPTIONpmkstat provides a one line summary of system performance every interval
unit of time (the default is 5 seconds). pmkstat 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.
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, pmkstat 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 root privileges are required to
retrieve the required metrics directly. In this case, metrics are
fetched from the local host using the standalone PM_CONTEXT_LOCAL variant
of pmNewContext(3). When the -h option is specified, pmkstat connects to
the pmcd(1) on host and fetches metrics from there.
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.
Standalone mode can only connect to the local host, using an archive
implies a host name, and nominating a host precludes using an archive, so
the options -L, -a and -h are mutually exclusive.
Normally pmkstat operates on the default Performance Metrics Name Space
(PMNS), however if the -n option is specified an alternative namespace is
loaded from the file pmnsfile.
If the -s the option is specified, samples defines the number of samples
to be retrieved and reported. If samples is 0 or -s is not specified,
pmkstat 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.
Also when using archives, the -d option requests that the prevailing
real-time delay be applied between samples (see -t) to effect a pause,
rather than the default behavior of replaying at full speed.
The output from pmkstat is directed to standard output, and the columns
in the report are interpreted as follows:
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PMKSTAT(1)PMKSTAT(1)
runq Average number of runnable processes in main memory (run) and
in swap memory (swp) during the interval.
memory The free column indicates average free memory during the
interval, in Kbytes. The page column is the average number of
page out operations per second during the interval. I/Os
caused by these page out operations are included in the write
I/O rate (see disks, below).
system System call rate (scall), context switch rate (ctxsw) and
interrupt rate (intr). Rates are expressed as average
operations per second during the interval.
disks Aggregated physical read (rd) and write (wr) rates over all
disks, expressed as physical I/Os issued per second during the
interval.
cpu Percentage of CPU time spent executing user code (usr), system
and interrupt code (sys), idle loop (idl) and idle waiting for
resources, typically disk I/O (wt).
The meanings of idl and wt changed in the IRIX 6.5.13 release.
For details, see the -U section of the sar(1) man page.
If any values for the associated performance metrics are unavailable, the
value appears as ``?'' in the output.
By default, pmkstat reports the time of day according to the local
timezone on the system where pmkstat 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.
NOTES
The interrupt (intr) rate includes the high frequency clock (and possibly
some video-related and/or audio-related interrupts), and differs widely,
even on idle systems, depending upon the hardware configuration. A more
useful measure would be the delta above the quiescent interrupt rate on
an idle system, but we have no way of measuring this.
FILES
$PCP_VAR_DIR/pmns/*
default PMNS specification files
$PCP_VAR_DIR/config/pmlogger/config.pmkstat
pmlogger(1) configuration for creating an archive suitable for
replay with pmkstatPCP 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
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PMKSTAT(1)PMKSTAT(1)
$PCP_CONF variable may be used to specify an alternative configuration
file, as described in pcp.conf(4).
SEE ALSOPCPIntro(1), pmchart(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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