pmdalio is a Performance Metrics Domain Agent (PMDA) which exports metric values about the Linux I/O target subsystem, which provides for protocols like iSCSI, FCP, FCoE. These allow storage available on one host to be exported and consumed by other hosts using industry standard protocols.
This PMDA exports summary metrics which are performance value aggregations and configuration per LIO target instance. Additionally, it provides per LUN performance metrics including IOPS, and READ and WRITE throughput.
The LIO configuration is maintained within the kernel's configfs virtual filesystem. The python-rtslib module provides an interface to configfs, allowing tools like pmdalio to interact with the settings and metadata held in configfs.
Install the lio PMDA by using the Install script as root:
# cd $PCP_PMDAS_DIR/lio # ./Install
To uninstall, do the following as root:
# cd $PCP_PMDAS_DIR/lio # ./Remove
pmdalio 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.
installation script for the pmdalio agent
undo installation script for the pmdalio agent
default log file for error messages from pmdalio
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).
PCPIntro(1), pmcd(1), pminfo(1) and pmpython(1).