NAME

       pmlogcheck - checks for invalid data in a PCP archive

SYNOPSIS

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

DESCRIPTION

       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

       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 starttime.

       -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 host.

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

OPERATION

       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 archive.index.

       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 archive.meta.

   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 date).

FILES

       $PCP_VAR_DIR/pmns/*
            default PMNS specification files

       $PCP_LOG_DIR/pmlogger/<hostname>
            default directory for PCP archives containing performance data collected from the host hostname.

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).

SEE ALSO

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

Performance Co-Pilot                                   PCP                                         PMLOGCHECK(1)