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 [-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]
21
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.
29 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).
37 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 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:
47 -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.
56 -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.
61 -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.
67 -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).
71
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.
76
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.
83
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).
90
92 PCPIntro(1), dbpmda(1), pmcd(1), pcp.conf(5) and pcp.env(5).
93Performance Co-Pilot PCP KERNEL_PMDAS(1)