1KERNEL PMDAS(1)             General Commands Manual            KERNEL PMDAS(1)
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NAME

6       pmdaaix,  pmdadarwin,  pmdafreebsd, pmdalinux, pmdanetbsd, pmdasolaris,
7       pmdawindows - operating system kernel performance metrics domain agents
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SYNOPSIS

10       $PCP_PMDAS_DIR/aix/pmdaaix [-d domain] [-l logfile] [-U username]
11       $PCP_PMDAS_DIR/darwin/pmdadarwin [-d domain] [-l logfile] [-U username]
12       $PCP_PMDAS_DIR/freebsd/pmdafreebsd [-d domain] [-l logfile]  [-U  user‐
13       name]
14       $PCP_PMDAS_DIR/linux/pmdalinux [-d domain] [-l logfile] [-U username]
15       $PCP_PMDAS_DIR/netbsd/pmdanetbsd [-d domain] [-l logfile] [-U username]
16       $PCP_PMDAS_DIR/solaris/pmdasolaris  [-d  domain] [-l logfile] [-U user‐
17       name]
18       $PCP_PMDAS_DIR/windows/pmdawindows [-d domain] [-l logfile]  [-U  user‐
19       name]
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DESCRIPTION

22       Each  supported  platform has a kernel Performance Metrics Domain Agent
23       (PMDA) which extracts performance metrics from the kernel of that plat‐
24       from.   A  variety  of platform-specific metrics are available, with an
25       equally varied set of access mechanisms - typically this involves  spe‐
26       cial  system calls, or reading from files in kernel virtual filesystems
27       such as the Linux sysfs and procfs filesystems.
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29       The platform kernel PMDA is one of the most critical components of  the
30       PCP  installation,  and  must be as efficient and reliable as possible.
31       In all installations the default kernel PMDA will  be  installed  as  a
32       shared  library  and thus executes directly within the pmcd(1) process.
33       This slightly reduces overheads associated with querying  the  metadata
34       and  values  associated  with  these  metrics  (no  message  passing is
35       required).
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37       Unlike many other PMDAs, the kernel PMDA exports  a  number  of  metric
38       namespace  subtrees,  such as kernel, network, swap, mem, ipc, filesys,
39       nfs, disk and hinv (hardware inventory).
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41       Despite usually running as shared libraries,  most  installations  also
42       include  a  stand-alone executable for the kernel PMDA.  This is to aid
43       profiling and debugging activities, with  dbpmda(1)  for  example.   In
44       this  case  (but  not for shared libraries), the following command line
45       options are available:
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47       -d   It is absolutely crucial that the performance metrics domain  num‐
48            ber  specified  here  is  unique  and consistent.  That is, domain
49            should be different for every PMDA on the one host, and  the  same
50            domain number should be used for the same PMDA on all hosts.
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52       -l   Location  of  the  log  file.  By default, a log file named [plat‐
53            form].log is written in the  current  directory  of  pmcd(1)  when
54            pmda[platform]  is  started,  i.e.  $PCP_LOG_DIR/pmcd.  If the log
55            file cannot be created or is not writable, output  is  written  to
56            the standard error instead.
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58       -U   User  account  under  which  to run the agent.  The default is the
59            unprivileged "pcp" account in current  versions  of  PCP,  but  in
60            older versions the superuser account ("root") was used by default.
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INSTALLATION

63       Access  to  the  names, help text and values for the kernel performance
64       metrics is available by default - unlike most other agents,  no  action
65       is required to enable them and they should not be removed.
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FILES

68       $PCP_PMDAS_DIR/[platform]/help
69                 default help text file for the the kernel metrics
70       $PCP_LOG_DIR/pmcd/[platform].log
71                 default  log  file  for  error messages and other information
72                 from the kernel PMDA.
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PCP ENVIRONMENT

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

82       PCPIntro(1), dbpmda(1) pmcd(1), pcp.conf(5) and pcp.env(5).
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86Performance Co-Pilot                  PCP                      KERNEL PMDAS(1)
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