PMDAKVM(1)

NAME
pmdakvm - Linux virtualization performance metrics domain agent (PMDA)

SYNOPSIS
$PCP_PMDAS_DIR/kvm/pmdakvm [-D debug]

DESCRIPTION
pmdakvm is a Performance Metrics Domain Agent (PMDA) which exports metric values from the Linux KVM (Kernel Virtual Machine) virtualization subsystem.

Per-processor KVM trace metrics from the kernel events enumerated below /sys/kernel/debug/tracing/events/kvm can be configured statically using the pmdakvm configuration file, /etc/pcp/kvm/kvm.conf.

INSTALLATION
Optionally configure trace points in the configuration file, then install the KVM PMDA by using the Install script as root:

    # cd $PCP_PMDAS_DIR/kvm
    # ./Install

To uninstall, do the following as root:

    # cd $PCP_PMDAS_DIR/kvm
    # ./Remove

pmdakvm is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed.

CAVEATS
When pmdakvm is running, it holds references to kernel resources within the KVM device driver. It is thus not possible to unload or reload the device driver module while the PMDA is running. The ideal procedure to follow in order to reload the kernel module is the reverse of that described in the ``INSTALLATION'' section above - i.e. first run ./Remove, then reload the kernel module, then run ./Install.

FILES

$PCP_SYSCONF_DIR/kvm/kvm.conf
    configuration file for the pmdakvm agent

$PCP_PMDAS_DIR/kvm/Install
    installation script for the pmdakvm agent

$PCP_PMDAS_DIR/kvm/Remove
    undo installation script for the pmdakvm agent

$PCP_LOG_DIR/pmcd/kvm.log
    default log file for error messages from pmdakvm

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).

DEBUGGING OPTIONS
The -D or --debug option enables the output of additional diagnostics on stderr to help triage problems, although the information is sometimes cryptic and primarily intended to provide guidance for developers rather than for end-users. debug is a comma separated list of debugging options; use pmdbg(1) with the -l option to obtain a list of the available debugging options and their meaning.

SEE ALSO
PCPIntro(1), pmcd(1) and kvm(1).