NAME

pmdalustre - lustre filesystem statistics performance metrics domain agent (PMDA)

DESCRIPTION

pmdalustre is a Performance Metrics Domain Agent (PMDA) which reads and exports metric values from the statistics interfaces of a Lustre filesystem.

pmdalustre searches for statistics interfaces from several locations, which vary depending on the version of Lustre installed locally.

Recent Lustre versions (v2.12 and later) export statistics from the kernel debugfs pseudo filesystem, in the directories /sys/kernel/debug/lustre/llite and /sys/kernel/debug/lnet. If these interfaces are not found during startup, pmdalustre will automatically check if the statistics interfaces are available from the procfs pseudo filesystem below the /proc/fs/lustre/llite and /proc/sys/lnet directories. These are the default locations of the statistics for Lustre versions less than v2.12.

If neither of the above filesystem interfaces are detected, or if the user wants to override the default locations, pmdalustre also supports an optional configuration file named $PCP_PMDAS_DIR/lustre/lustre.conf. Note that $PCP_PMDAS_DIR is set to /var/lib/pcp/pmdas on most Linux based systems. The configuration file supports perl(1) variable assignment syntax. An example configuration file suitable for Lustre v2.12 and later is:

$LLITE_PATH="/sys/kernel/debug/lustre/llite/";
$LNET_PATH="/sys/kernel/debug/lustre/lnet/";

Finally, overriding all of the above, the LUSTRE_LLITE_PATH and LUSTRE_LNET_PATH environment variables may be set (and exported) to specify the directory locations of the statistics interfaces to be used. This mechanism using environment variabes is intended to be used for development and testing purposes only.

The pmdalustre process runs as the root user because debugfs directories are not normally readable by unprivileged users.

INSTALLATION

Install pmdalustre by using the Install script as the root user:

# cd $PCP_PMDAS_DIR/lustre
# ./Install

If you want to undo the installation, do the following as root:

# cd $PCP_PMDAS_DIR/lustre
# ./Remove

pmdalustre 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.

FILES

$PCP_PMDAS_DIR/lustre/Install

installation script for the pmdalustre agent

$PCP_PMDAS_DIR/lustre/Remove

undo installation script for the pmdalustre agent

$PCP_LOG_DIR/pmcd/lustre.log

default log file for error messages from pmdalustre

$PCP_PMDAS_DIR/lustre/lustre.conf

Configuration file for over-riding default statistics directories used by pmdalustre.

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), perl(1), pmcd(1) and llstat(1).