NAME

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

SYNOPSIS

       $PCP_PMDAS_DIR/aix/pmdaaix [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/darwin/pmdadarwin [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/freebsd/pmdafreebsd [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/linux/pmdalinux [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/netbsd/pmdanetbsd [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/solaris/pmdasolaris [-d domain] [-l logfile] [-U username]
       $PCP_PMDAS_DIR/windows/pmdawindows [-d domain] [-l logfile] [-U username]

DESCRIPTION

       Each supported platform has a kernel Performance Metrics Domain Agent (PMDA) which  extracts  performance
       metrics  from the kernel of that platfrom.  A variety of platform-specific metrics are available, with an
       equally varied set of access mechanisms - typically this involves special system calls, or  reading  from
       files in kernel virtual filesystems such as the Linux sysfs and procfs filesystems.

       The  platform  kernel PMDA is one of the most critical components of the PCP installation, and must be as
       efficient and reliable as possible.  In all installations the default kernel PMDA will be installed as  a
       shared  library  and  thus executes directly within the pmcd(1) process.  This slightly reduces overheads
       associated with querying the metadata and values associated with these metrics  (no  message  passing  is
       required).

       Unlike  many  other PMDAs, the kernel PMDA exports a number of metric namespace subtrees, such as kernel,
       network, swap, mem, ipc, filesys, nfs, disk and hinv (hardware inventory).

       Despite usually running as shared libraries, most installations also include a stand-alone executable for
       the kernel PMDA.  This is to aid profiling and debugging activities, with dbpmda(1) for example.  In this
       case (but not for shared libraries), the following command line options are available:

       -d   It is absolutely crucial that the performance metrics domain number specified  here  is  unique  and
            consistent.  That is, domain should be different for every PMDA on the one host, and the same domain
            number should be used for the same PMDA on all hosts.

       -l   Location of the log file.  By default, a log file named [platform].log is  written  in  the  current
            directory  of  pmcd(1)  when  pmda[platform]  is  started, i.e.  $PCP_LOG_DIR/pmcd.  If the log file
            cannot be created or is not writable, output is written to the standard error instead.

       -U   User account under which to run the agent.  The default is the unprivileged "pcp" account in current
            versions of PCP, but in older versions the superuser account ("root") was used by default.

INSTALLATION

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

FILES

       $PCP_PMDAS_DIR/[platform]/help
                 default help text file for the the kernel metrics
       $PCP_LOG_DIR/pmcd/[platform].log
                 default log file for error messages and other information from the kernel PMDA.

PCP ENVIRONMENT

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

SEE ALSO

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