1PMLOGCHECK(1)               General Commands Manual              PMLOGCHECK(1)
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NAME

6       pmlogcheck - checks for invalid data in a PCP archive
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SYNOPSIS

9       pmlogcheck  [-lwz]  [-n  pmnsfile] [-S start] [-T finish] [-Z timezone]
10       archive
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DESCRIPTION

13       pmlogcheck prints information about the  nature  of  any  invalid  data
14       which it detects in the files of a PCP archive.
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16       The  archive  has  the  base name archive and must have been previously
17       created using pmlogger(1).
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19       Normally pmlogcheck operates on the default  Performance  Metrics  Name
20       Space  (pmns(5)),  however if the -n option is specified an alternative
21       namespace is loaded from the file pmnsfile.
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23       The command line options -S and -T can be used to specify a time window
24       over  which  metrics  should  be  checked in Pass 3 (see below).  These
25       options are common to many Performance Co-Pilot  tools  and  are  fully
26       described in PCPIntro(1).
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28       The -l option prints the archive label, showing the log format version,
29       the time and date for the start and (current) end of the  archive,  and
30       the host from which the performance metrics values were collected.
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32       By  default,  pmlogcheck reports the time of day according to the local
33       timezone on the system where pmlogcheck is run.  The -Z option  changes
34       the  timezone  to timezone in the format of the environment variable TZ
35       as described in environ(7).  The -z option changes the timezone to  the
36       local  timezone  at the host that is the source of the performance met‐
37       rics, as specified in the label record of the archive log.
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39       The checking proceeds in a number of passes, each designed to  validate
40       progressively  more complex semantic relationships between the informa‐
41       tion in a PCP archive.
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Pass 0

44       Each physical file of the PCP archive is processed to ensure the  label
45       records  are valid and consistent, and that each file contains an inte‐
46       gral number of physical records with correct header and trailer fields.
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48       Any errors at this stage are usually fatal.  The PCP archive is  proba‐
49       bly  damaged  beyond  repair,  and  no  more  passes  of pmlogcheck are
50       attempted.
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Pass 1

53       Validates the integrity of the temporal index, usually archive.index.
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55       As the temporal index is (strictly speaking) optional, errors  at  this
56       stage  are  handled by marking the index as bad and ignoring it for the
57       remainder of the pmlogcheck passes.
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59       Permanent repair can be achieved by removing the  temporal  index  file
60       and  then  making  a  copy  of the PCP archive using pmlogrewrite(1) or
61       pmlogextract(1).  This will create a new temporal index for the  copied
62       archive as a side-effect.
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Pass 2

65       Validates the integrity of the metadata file, usually archive.meta.
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Pass 3

68       Validates  the integrity of each of the log volumes of the PCP archive,
69       usually archive.0, archive.1, etc.
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71       There is some basic integrity checks to ensure the encoding  of  values
72       for  each  metric  remains  consistent  and  the values are well formed
73       across all the observations in the archive.
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75       Also the timestamps for the observations are expected to  be  monotoni‐
76       cally increasing as the archive is tranversed.
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78       Additional   attention   is   given   to  counter  metrics  (type  from
79       pmLookupDesc(3) is PM_SEM_COUNTER) which are expected to have monotoni‐
80       cally  increasing  values.   If the values are not monotonic increasing
81       this may suggest a counter wrap has happened or  there  has  been  some
82       interruption  or reset to the underlying source of the performance data
83       that is no captured in the archive.
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85       For each counter metric which has been detected as  having  wrapped  at
86       some  point  in  the archive, pmlogcheck produces output describing the
87       metric name (with instance identifiers where appropriate), the internal
88       storage type for the metric, the value of the metric before the counter
89       wrap (with its associated timestamp), and the value of the metric after
90       the wrap (also with a timestamp).
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92       The -w option may be used to suppress reporting of counter wraps.
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94       pmlogcheck  produces  two different timestamp formats, depending on the
95       interval over which it is run.  For an interval greater than 24  hours,
96       the date is displayed in addition to the time at which the counter wrap
97       occurred.  If the extent of the data being  checked  is  less  than  24
98       hours,  a more precise format is used (time is displayed with millisec‐
99       ond precision, but without the date).
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FILES

102       $PCP_VAR_DIR/pmns/*
103                 default PMNS specification files
104       $PCP_LOG_DIR/pmlogger/hostname
105                 default directory for  PCP  archives  containing  performance
106                 data collected from the host hostname.
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PCP ENVIRONMENT

109       Environment variables with the prefix PCP_ are used to parameterize the
110       file and directory names used by PCP.  On each installation,  the  file
111       /etc/pcp.conf  contains  the  local  values  for  these variables.  The
112       $PCP_CONF variable may be used to specify an alternative  configuration
113       file, as described in pcp.conf(5).
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SEE ALSO

116       PCPIntro(1),    pmdumplog(1),   pmlogextract(1),   pmlogger(1),   pmlo‐
117       grewrite(1), pmlogsummary(1), pmval(1),  pmLookupDesc(3),  pcp.conf(5),
118       pcp.env(5) and pmns(5).
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DIAGNOSTICS

121       All  are  generated  on  standard  error  and  are intended to be self-
122       explanatory.
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126Performance Co-Pilot                  PCP                        PMLOGCHECK(1)
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