1PMSNAP(1) General Commands Manual PMSNAP(1)
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6 pmsnap - generate performance summary snapshot images
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9 $PCP_BINADM_DIR/pmsnap [-NV] [-C dir] [-c configs] [-n names] [-o dir]
10 [-t type]
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13 pmsnap is a shell script that is normally run periodically from
14 crontab(1) to generate graphic images of pmchart(1) performance charts.
15 These images can be in any of the supported pmchart formats, including
16 png, bmp, and jpeg, and may be incorporated into the content offered by
17 the local Web server. The -V option enables verbose tracing of the
18 actions. By default pmsnap generates no output unless some error or
19 warning condition is encountered.
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21 pmsnap generates images according to its control file, $PCP_PMSNAPCON‐
22 TROL_PATH (or dir/control if the -C option is specified), and uses ar‐
23 chive logs created by pmlogger(1) or PCP archive folios created by
24 pmafm(1) and pmlogger_check(1). Before attempting to configure pmsnap,
25 it is strongly recommended that pmlogger be configured according to the
26 descriptions in pmlogger_daily(1), pmlogger_check(1) and pmlogger(1).
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28 Once pmlogger has been configured, it is necessary to configure pmsnap
29 as follows;
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31 1. Edit the control file $PCP_PMSNAPCONTROL_PATH. The syntax of
32 this file is described in the comment at the head of the file
33 and an example is supplied for one and twelve hour "Summary"
34 performance charts for the local host. Suitable arguments for
35 pmchart are also described in the comment. The user should con‐
36 sult pmchart for further details. Note that when pmsnap is run,
37 it globally substitutes the string LOCALHOSTNAME with the name
38 of the local host in the control file.
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40 2. Test the configuration by running
41 $PCP_BINADM_DIR/pmsnap.
42 Without any arguments pmsnap will process every non-comment line
43 in $PCP_PMSNAPCONTROL_PATH. The output images will be placed in
44 the files named in the first field of each line in the control
45 file, with the file format appended if necessary. If these file
46 names do not start with / or . then they are assumed relative
47 to dir, as specified with the -o option. The default dir is the
48 current directory. Note that if pmlogger has only been recently
49 started (within about the last 15 minutes), snap-shot images may
50 not be produced and no error messages will be issued - the rea‐
51 son is that pmchart can not use very short archives and hence,
52 neither can pmsnap. For debugging purposes the -V flag should
53 be used.
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55 3. Add an appropriate entry for pmsnap in the root user's crontab.
56 An example is supplied in $PCP_VAR_DIR/config/pmlogger/crontab.
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58 4. Incorporate the pmsnap images into the local WWW content. Usu‐
59 ally, WWW pages use images that are relative to a particular
60 document root, so it is often convenient to use the -o command
61 line option to specify a sub-directory of the local WWW content,
62 and then create a web page in this directory that shows the
63 snapshot images with text and other content appropriate to the
64 local environment.
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67 pmsnap accepts the following command line options;
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69 -C dir The control file is located in the directory dir rather than in
70 the default $PCP_PMSNAPCONTROL_PATH location.
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72 -c config-pattern
73 Only process lines in the control file which match the config-
74 pattern regular expression in the Config column.
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76 -n name-pattern
77 Only process lines in the control file which match the name-pat‐
78 tern regular expression (see egrep(1)) in the Name column.
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80 -o dir The output images having file names which do not start with / or
81 . will be placed in a directory relative to dir, otherwise the
82 output directory is relative to the current directory (i.e. the
83 default value for dir is ./). Note that dir must be a writable
84 directory path and may be on an NFS or CIFS file system.
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86 The -N option enables a ``show me'' mode, where the actions are echoed,
87 but not executed, in the style of ``make -n''. Using -N in conjunction
88 with -V maximizes the diagnostic capabilities for debugging.
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90 When either -n or -c are used, pmsnap will only process lines in the
91 control file which match all the supplied patterns. If no patterns are
92 given, then all lines will be processed. These arguments allow multi‐
93 ple entries for pmsnap in crontab so that different performance summary
94 images can be generated at different times or with different frequen‐
95 cies.
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97 A sample HTML page, suitable for the Summary snapshot may be found in
98 $PCP_VAR_DIR/config/pmsnap/Summary.html.
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100 Although pmsnap attempts to flush stdio(3) output buffers in the rele‐
101 vant pmlogger processes before generating snap-shots images, this may
102 fail for assorted reasons and no error message will be given.
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104 pmsnap should not be invoked immediately after pmlogger_daily has
105 rolled the logs because the new archive logs will be too short to
106 obtain meaningful results. Note however that pmsnap will not report
107 errors from pmchart about not being able to comply with the -A option
108 on very short archives. In these cases no error will be reported and
109 no output images will be produced.
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112 $PCP_PMSNAPCONTROL_PATH
113 pmsnap control file
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115 $PCP_VAR_DIR/config/pmsnap/Summary
116 summary view for pmchart
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118 $PCP_VAR_DIR/config/pmsnap/Summary.html
119 sample HTML page for summary snapshot
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121 $PCP_LOG_DIR/pmlogger/hostname/Latest
122 PCP archive folio for the host hostname, as generated by
123 pmlogger_check
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125 $PCP_VAR_DIR/config/pmlogger/crontab
126 example crontab entry
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129 cron(1), crontab(1), egrep(1), pmchart(1), pmafm(1), pmlc(1), pmlog‐
130 ger(1), pmlogger_daily(1), X(1), and Xvfb(1).
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134Performance Co-Pilot PMSNAP(1)