1PMLOGCHECK(1) General Commands Manual PMLOGCHECK(1)
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6 pmlogcheck - checks for invalid data in a PCP archive
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9 pmlogcheck [-lmvwz?] [-n pmnsfile] [-S start] [-T finish] [-Z time‐
10 zone] archive
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13 pmlogcheck prints information about the nature of any invalid data
14 which it detects in the files of a PCP archive.
15 The archive has the base name archive and must have been previously
17 created using pmlogger(1).
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20 The available command line options are:
21 -l, --label
23 Print the archive label, showing the log format version, the time
24 and date for the start and (current) end of the archive, and the
25 host from which the performance metrics values were collected.
26 -m, --metadataonly
28 Skip Pass 3 (see below) and only check the archive meta data.
29 This can run substantially faster in cases where the volume data
30 doesn't need to be checked, especially on archives with compressed
31 data volume(s).
32 -n pmnsfile, --namespace=pmnsfile
34 Load an alternative Performance Metrics Name Space (PMNS(5)) from
35 the file pmnsfile.
36 -S starttime, --start=starttime
38 Specify the starttime of time window over which metrics should be
39 checked in Pass 3 (see below). Refer to PCPIntro(1) for a com‐
40 plete description of the syntax for starttime.
41 -T endtime, --finish=endtime
43 Specify the endtime of time window over which metrics should be
44 checked in Pass 3 (see below). Refer to PCPIntro(1) for a com‐
45 plete description of the syntax for endtime.
46 -v, --verbose
48 Enable verbose mode.
49 -z, --hostzone
51 Use the local timezone of the host that is the source of the per‐
52 formance metrics archive. The default is to use the timezone of
53 the local host.
54 -Z timezone, --timezone=timezone
56 Use timezone for the date and time. Timezone is in the format of
57 the environment variable TZ as described in environ(7). The
58 default is to use the timezone of the local host.
59 -?, --help
61 Display usage message and exit.
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64 The checking proceeds in a number of passes, each designed to validate
65 progressively more complex semantic relationships between the informa‐
66 tion in a PCP archive.
67 Pass 0
69 Each physical file of the PCP archive is processed to ensure the label
70 records are valid and consistent, and that each file contains an inte‐
71 gral number of physical records with correct header and trailer fields.
72 Any errors at this stage are usually fatal. The PCP archive is proba‐
74 bly damaged beyond repair, and no more passes of pmlogcheck are
75 attempted.
76 Pass 1
78 Validates the integrity of the temporal index, usually archive.index.
79 As the temporal index is (strictly speaking) optional, errors at this
81 stage are handled by marking the index as bad and ignoring it for the
82 remainder of the pmlogcheck passes.
83 Permanent repair can be achieved by removing the temporal index file
85 and then making a copy of the PCP archive using pmlogrewrite(1) or
86 pmlogextract(1). This will create a new temporal index for the copied
87 archive as a side-effect.
88 Pass 2
90 Validates the integrity of the metadata file, usually archive.meta.
91 Pass 3
93 Validates the integrity of each of the log volumes of the PCP archive,
94 usually archive.0, archive.1, etc.
95 There is some basic integrity checks to ensure the encoding of values
97 for each metric remains consistent and the values are well formed
98 across all the observations in the archive.
99 Also the timestamps for the observations are expected to be monotoni‐
101 cally increasing as the archive is tranversed.
102 Additional attention is given to counter metrics (type from
104 pmLookupDesc(3) is PM_SEM_COUNTER) which are expected to have monotoni‐
105 cally increasing values. If the values are not monotonic increasing
106 this may suggest a counter wrap has happened or there has been some
107 interruption or reset to the underlying source of the performance data
108 that is no captured in the archive.
109 For each counter metric which has been detected as having wrapped at
111 some point in the archive, pmlogcheck produces output describing the
112 metric name (with instance identifiers where appropriate), the internal
113 storage type for the metric, the value of the metric before the counter
114 wrap (with its associated timestamp), and the value of the metric after
115 the wrap (also with a timestamp).
116 The -w option may be used to suppress reporting of counter wraps.
118 pmlogcheck produces two different timestamp formats, depending on the
120 interval over which it is run. For an interval greater than 24 hours,
121 the date is displayed in addition to the time at which the counter wrap
122 occurred. If the extent of the data being checked is less than 24
123 hours, a more precise format is used (time is displayed with millisec‐
124 ond precision, but without the date).
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127 All are generated on standard error and are intended to be self-
128 explanatory.
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131 $PCP_VAR_DIR/pmns/*
132 default PMNS specification files
133 $PCP_LOG_DIR/pmlogger/<hostname>
135 default directory for PCP archives containing performance data
136 collected from the host hostname.
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139 Environment variables with the prefix PCP_ are used to parameterize the
140 file and directory names used by PCP. On each installation, the file
141 /etc/pcp.conf contains the local values for these variables. The
142 $PCP_CONF variable may be used to specify an alternative configuration
143 file, as described in pcp.conf(5).
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146 PCPIntro(1), pmdumplog(1), pmlogextract(1), pmlogger(1), pmlo‐
147 grewrite(1), pmlogsummary(1), pmLookupDesc(3), pcp.conf(5), pcp.env(5)
148 and PMNS(5).
149Performance Co-Pilot PCP PMLOGCHECK(1)