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  [-A] [-d domain] [-l logfile] [-U user‐
15       name]
16       $PCP_PMDAS_DIR/netbsd/pmdanetbsd [-d domain] [-l logfile] [-U username]
17       $PCP_PMDAS_DIR/solaris/pmdasolaris [-d domain] [-l logfile]  [-U  user‐
18       name]
19       $PCP_PMDAS_DIR/windows/pmdawindows  [-d  domain] [-l logfile] [-U user‐
20       name]
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DESCRIPTION

23       Each supported platform has a kernel Performance Metrics  Domain  Agent
24       (PMDA) which extracts performance metrics from the kernel of that plat‐
25       from.  A variety of platform-specific metrics are  available,  with  an
26       equally  varied set of access mechanisms - typically this involves spe‐
27       cial system calls, or reading from files in kernel virtual  filesystems
28       such as the Linux sysfs and procfs filesystems.
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30       The  platform kernel PMDA is one of the most critical components of the
31       PCP installation, and must be as efficient and  reliable  as  possible.
32       In  all  installations  the  default kernel PMDA will be installed as a
33       shared library and thus executes directly within the  pmcd(1)  process.
34       This  slightly  reduces overheads associated with querying the metadata
35       and values associated with these metrics (no  message  passing  is  re‐
36       quired).
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38       Unlike  many  other  PMDAs,  the kernel PMDA exports a number of metric
39       namespace subtrees, such as kernel, network, swap, mem,  ipc,  filesys,
40       nfs, disk and hinv (hardware inventory).
41
42       Despite  usually  running  as shared libraries, most installations also
43       include a stand-alone executable for the kernel PMDA.  This is  to  aid
44       profiling  and  debugging  activities,  with dbpmda(1) for example.  In
45       this case (but not for shared libraries), the  following  command  line
46       options are available:
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48       -A   Disables  use  of  the credentials provided by PMAPI client tools,
49            and simply runs everything under the "root" account.  Only  enable
50            this  option  if  you  understand the risks involved, and are sure
51            that all remote accesses will be from benevolent  users.   If  en‐
52            abled, unauthenticated remote PMAPI clients will be able to access
53            potentially sensitive performance metric values which an unauthen‐
54            ticated  PMAPI  client  usually  would  not  be able to.  Refer to
55            CVE-2012-3419 for additional details.
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57       -d   It is absolutely crucial that the performance metrics domain  num‐
58            ber  specified  here  is  unique  and consistent.  That is, domain
59            should be different for every PMDA on the one host, and  the  same
60            domain number should be used for the same PMDA on all hosts.
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62       -l   Location  of  the  log  file.  By default, a log file named [plat‐
63            form].log is written in the  current  directory  of  pmcd(1)  when
64            pmda[platform]  is  started,  i.e.  $PCP_LOG_DIR/pmcd.  If the log
65            file cannot be created or is not writable, output  is  written  to
66            the standard error instead.
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68       -U   User  account under which to run the agent.  The default is either
69            the privileged "root" account on some platforms (Linux, for  exam‐
70            ple) or the unprivileged "pcp" account (wherever possible).
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INSTALLATION

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

78       $PCP_PMDAS_DIR/[platform]/help
79                 default help text file for the the kernel metrics
80       $PCP_LOG_DIR/pmcd/[platform].log
81                 default  log  file  for  error messages and other information
82                 from the kernel PMDA.
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PCP ENVIRONMENT

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

92       PCPIntro(1), dbpmda(1), pmcd(1), pcp.conf(5) and pcp.env(5).
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