pcp-tapestat(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | REPORT | PCP ENVIRONMENT | SEE ALSO | COLOPHON

PCP-TAPESTAT(1)          General Commands Manual         PCP-TAPESTAT(1)

NAME         top

       pcp-tapestat - report tape I/O statistics

SYNOPSIS         top

       pcp [pcp options] tapestat [-u?]  [-G method] [-P precision] [-R
       pattern] [-x [t][,h][,noidle]]

DESCRIPTION         top

       pcp-tapestat reports I/O statistics for tape devices.

OPTIONS         top

       When invoked via the pcp(1) command, the pcp options -A/--align,
       -a/--archive, -h/--host, -O/--origin, -S/--start, -s/--samples,
       -t/--interval, -T/--finish, -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-tapestat
       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 'st(0|1)$' is specified,
            the device column will be sum(st(0|1)$) and summed
            statistics for st0 and st1 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.  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. '^st[0-9]+' will match all device names
            starting with 'st' followed by one or more numbers.  e.g.
            '^st(0|1)$' will only match 'st0' and 'st1'.  e.g. 'st0$'
            will match 'st0' but not 'st1'.  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:
            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.

REPORT         top

       The columns in the pcp-tapestat 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 tape device name.  When -G is specified,
              this is replaced by the aggregation method and regular
              expression - see the -G and -R options above.

       r/s    The number of reads issued expressed as the number per
              second averaged over the interval.

       w/s    The number of writes issued expressed as the number per
              second averaged over the interval.

       kb_r/s The amount of data read expressed in kilobytes per second
              averaged over the interval.

       kb_w/s The amount of data written expressed in kilobytes per
              second averaged over the interval.

       r_pct  Read percentage wait - the percentage of time over the
              interval spent waiting for read requests to complete.  The
              time is measured from when the request is dispatched to
              the SCSI mid-layer until it signals that it completed.

       w_pct  Write percentage wait - the percentage of time over the
              interval spent waiting for write requests to complete.
              The time is measured from when the request is dispatched
              to the SCSI mid-layer until it signals that it completed.

       o_pct  Overall percentage wait - the percentage of time over the
              interval spent waiting for any I/O request to complete
              (read, write, and other).

       Rs/s   The number of I/Os, expressed as the number per second
              averaged over the interval, where a non-zero residual
              value was encountered.

       o_cnt  The  number of I/Os, expressed as the number per second
              averaged over the interval, that were included as "other".
              Other I/O includes ioctl calls made to the tape driver and
              implicit operations performed by the tape driver such as
              rewind on close (for tape devices that implement rewind on
              close).  It does not include any I/O performed using
              methods outside of the tape driver (e.g. via sg ioctls).

PCP ENVIRONMENT         top

       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).

SEE ALSO         top

       PCPIntro(1), pcp(1), pmcd(1), pmchart(1), pmlogger(1),
       pcp.conf(5) and pcp.env(5).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨http://www.pcp.io/⟩.  If you have a bug report for this manual
       page, send it to pcp@groups.io.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/performancecopilot/pcp.git⟩ on 2021-08-27.
       (At that time, the date of the most recent commit that was found
       in the repository was 2021-08-27.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Performance Co-Pilot               PCP                   PCP-TAPESTAT(1)