1KERNEL PMDAS(1) General Commands Manual KERNEL PMDAS(1)
2
6 pmdaaix, pmdadarwin, pmdafreebsd, pmdalinux, pmdanetbsd, pmdasolaris,
7 pmdawindows - operating system kernel performance metrics domain agents
8
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]
20
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.
28 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).
36 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).
40 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:
46 -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.
51 -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.
57 -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.
61
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.
66
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.
73
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).
80
82 PCPIntro(1), dbpmda(1) pmcd(1), pcp.conf(5) and pcp.env(5).
83Performance Co-Pilot PCP KERNEL PMDAS(1)