отчет о статистике ввода-вывода блока (report block I/O statistics)
Имя (Name)
pmiostat, pcp-iostat - report block I/O statistics
Синопсис (Synopsis)
pcp [pcp options] iostat [-u?] [-G method] [-P precision] [-R
pattern] [-x [dm][,t][,h][,noidle]]
Описание (Description)
pcp-iostat reports I/O statistics for SCSI (by default) or other
devices (if the -x option is specified).
Параметры (Options)
When invoked via the pcp(1) command, the pcp options -A/--align,
-a/--archive, -h/--host, -O/--origin, -S/--start, -s/--samples,
-T/--finish, -t/--interval, -v/--version, -Z/--timezone and
-z/--hostzone become indirectly available; refer to PCPIntro(1)
for a complete description of these options.
The additional command line options available for pcp-iostat are:
-G method, --aggregate=method
Specifies that statistics for device names matching the
regular expression specified with the -R regex option should
be aggregated according to method. Note this is aggregation
based on matching device names (not temporal aggregation).
When -G is used, the device name column is reported as
method(regex), e.g. if -G sum -R 'sd(a|b)$' is specified,
the device column will be sum(sd(a|b)$) and summed
statistics for sda and sdb will be reported in the remaining
columns. If -G is specified but -R is not specified, then
the default regex is .*, i.e. matching all device names. If
method is sum then the statistics are summed. This includes
the %util column, which may therefore exceed 100% if more
than one device name matches. If method is avg then the
statistics are summed and then averaged by dividing by the
number of matching device names. If method is min or max,
the minimum or maximum statistics for matching devices are
reported, respectively.
-P N, --precision=N
This indicates the precision (number of decimal places) to
report. The default precision N may be set to something
other than the default (2). Note that the avgrq-sz and
avgqu-sz fields are always reported with N+1 decimals of
precision. These fields typically have values less than 1.
-R pattern, --regex=pattern
This restricts the report to device names matching a regular
expression pattern. The given pattern is searched as a perl
style regular expression, and will match any portion of a
device name. e.g. '^sd[a-zA-Z]+' will match all device
names starting with 'sd' followed by one or more alphabetic
characters. e.g. '^sd(a|b)$' will only match 'sda' and
'sdb'. e.g. 'sda$' will match 'sda' but not 'sdab'. See
also the -G option for aggregation options.
-u, --no-interpolation
When replaying a set of archives, by default values are
reported according to the requested sample interval (-t
option), not according to the actual interval recorded in
the archive(s). Without this option PCP interpolates the
values to be reported based on the records in the set of
archives, which is particularly useful when the -t option is
used to replay a set of archives with a longer sampling
interval than that with which the archive(s) was originally
recorded with. With the -u option, uninterpolated reporting
is enabled - every value is reported according to the native
recording interval in the set of archives. When the -u
option is specified, the -t option makes no sense and is
incompatible because the replay interval is always the same
as the recording interval in the set of archive. In
addition, -u only makes sense when replaying archives, see
the -a option on PCPIntro(1), and so if -u is specified then
-a must also be specified.
-V, --version
Display version number and exit.
-x comma-separated-options
Specifies a comma-separated list of one or more extended
reporting options as follows:
dm - report statistics for device-mapper logical devices
instead of SCSI devices,
t - prefix every line in the report with a timestamp in
ctime(3) format,
h - omit the heading, which is otherwise reported every 24
samples,
noidle - Do not display statistics for idle devices.
-?, --help
Display usage message and exit.
Отчет (Report)
The columns in the pcp-iostat report have the following
interpretation:
Timestamp
When the -x t option is specified, this column is the
timestamp in ctime(3) format.
Device Specifies the scsi device name, or if -x dm is specified,
the device-mapper logical device name. When -G is
specified, this is replaced by the aggregation method and
regular expression - see the -G and -R options above.
rrqm/s The number of read requests expressed as a rate per-second
that were merged during the reporting interval by the I/O
scheduler.
wrqm/s The number of write requests expressed as a rate per-
second that were merged during the reporting interval by
the I/O scheduler.
r/s The number of read requests completed by the device (after
merges), expressed as a rate per second during the
reporting interval.
w/s The number of write requests completed by the device
(after merges), expressed as a rate per second during the
reporting interval.
rkB/s The average volume of data read from the device expressed
as KBytes/second during the reporting interval.
wkB/s The average volume of data written to the device expressed
as KBytes/second during the reporting interval.
avgrq-sz
The average I/O request size for both reads and writes to
the device expressed as Kbytes during the reporting
interval.
avgqu-sz
The average queue length of read and write requests to the
device during the reporting interval.
await The average time in milliseconds that read and write
requests were queued (and serviced) to the device during
the reporting interval.
r_await
The average time in milliseconds that read requests were
queued (and serviced) to the device during the reporting
interval.
w_await
The average time in milliseconds that write requests were
queued (and serviced) to the device during the reporting
interval.
%util The percentage of time during the reporting interval that
the device was busy processing requests. A value of 100%
indicates device saturation.
Окружение PCP (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).
Смотри также (See also)
PCPIntro(1), pcp(1), iostat2pcp(1), pmcd(1), pmchart(1),
pmlogger(1), pcp.conf(5) and pcp.env(5).
