pmlogcheck(1) — Linux manual page


PMLOGCHECK(1)            General Commands Manual           PMLOGCHECK(1)

NAME         top

       pmlogcheck - checks for invalid data in a PCP archive

SYNOPSIS         top

       pmlogcheck [-lmvwz?]  [-n pmnsfile] [-S start] [-T finish] [-Z
       timezone] archive

DESCRIPTION         top

       pmlogcheck prints information about the nature of any invalid
       data which it detects in the files of a PCP archive.

       The archive has the base name archive and must have been
       previously created using pmlogger(1).

OPTIONS         top

       The available command line options are:

       -l, --label
            Print the archive label, showing the archive format version,
            the time and date for the start and (current) end of the
            archive, and the host from which the performance metrics
            values were collected.

       -m, --metadataonly
            Skip Pass 3 (see below) and only check the archive meta
            data.  This can run substantially faster in cases where the
            volume data doesn't need to be checked, especially on
            archives with compressed data volume(s).

       -n pmnsfile, --namespace=pmnsfile
            Load an alternative Performance Metrics Name Space (PMNS(5))
            from the file pmnsfile.

       -S starttime, --start=starttime
            Specify the starttime of time window over which metrics
            should be checked in Pass 3 (see below).  Refer to
            PCPIntro(1) for a complete description of the syntax for

       -T endtime, --finish=endtime
            Specify the endtime of time window over which metrics should
            be checked in Pass 3 (see below).  Refer to PCPIntro(1) for
            a complete description of the syntax for endtime.

       -v, --verbose
            Enable verbose mode.

       -w, --nowrap
            Suppress reporting of counter wraps.

       -z, --hostzone
            Use the local timezone of the host that is the source of the
            performance metrics archive.  The default is to use the
            timezone of the local host.

       -Z timezone, --timezone=timezone
            Use timezone for the date and time.  Timezone is in the
            format of the environment variable TZ as described in
            environ(7).  The default is to use the timezone of the local

       -?, --help
            Display usage message and exit.

OPERATION         top

       The checking proceeds in a number of passes, each designed to
       validate progressively more complex semantic relationships
       between the information in a PCP archive.

   Pass 0
       Each physical file of the PCP archive is processed to ensure the
       label records are valid and consistent, and that each file
       contains an integral number of physical records with correct
       header and trailer fields.

       Any errors at this stage are usually fatal.  The PCP archive is
       probably damaged beyond repair, and no more passes of pmlogcheck
       are attempted.

   Pass 1
       Validates the integrity of the temporal index, usually

       As the temporal index is (strictly speaking) optional, errors at
       this stage are handled by marking the index as bad and ignoring
       it for the remainder of the pmlogcheck passes.

       Permanent repair can be achieved by removing the temporal index
       file and then making a copy of the PCP archive using
       pmlogrewrite(1) or pmlogextract(1).  This will create a new
       temporal index for the copied archive as a side-effect.

   Pass 2
       Validates the integrity of the metadata file, usually

   Pass 3
       Validates the integrity of each of the volumes of the PCP
       archive, usually archive.0, archive.1, etc.

       There is some basic integrity checks to ensure the encoding of
       values for each metric remains consistent and the values are well
       formed across all the observations in the archive.

       Also the timestamps for the observations are expected to be
       monotonically increasing as the archive is tranversed.

       Additional attention is given to counter metrics (type from
       pmLookupDesc(3) is PM_SEM_COUNTER) which are expected to have
       monotonically increasing values.  If the values are not monotonic
       increasing this may suggest a counter wrap has happened or there
       has been some interruption or reset to the underlying source of
       the performance data that is no captured in the archive.

       For each counter metric which has been detected as having wrapped
       at some point in the archive, pmlogcheck produces output
       describing the metric name (with instance identifiers where
       appropriate), the internal storage type for the metric, the value
       of the metric before the counter wrap (with its associated
       timestamp), and the value of the metric after the wrap (also with
       a timestamp).

       The -w option may be used to suppress reporting of counter wraps.

       pmlogcheck produces two different timestamp formats, depending on
       the interval over which it is run.  For an interval greater than
       24 hours, the date is displayed in addition to the time at which
       the counter wrap occurred.  If the extent of the data being
       checked is less than 24 hours, a more precise format is used
       (time is displayed with millisecond precision, but without the

FILES         top

            default PMNS specification files

            default directory for PCP archives containing performance
            data collected from the host hostname.


       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

SEE ALSO         top

       PCPIntro(1), pmdumplog(1), pmlogextract(1), pmlogger(1),
       pmlogrewrite(1), pmlogsummary(1), pmLookupDesc(3), pcp.conf(5),
       pcp.env(5) and PMNS(5).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨⟩ on 2023-12-22.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-12-16.)  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

Performance Co-Pilot               PCP                     PMLOGCHECK(1)

Pages that refer to this page: pmlogdump(1)pmloglabel(1)pmlogsize(1)