pmdagfs2 — Global Filesystem v2 (GFS2) PMDA

Description

pmdagfs2 is a Performance Metrics Domain Agent (PMDA) which exports  metric values about mounted GFS2 filesystems from the debugfs filesystem.  This PMDA requires debugfs along with at least one mounted GFS2 filesystem to be mounted in order to be able to provide metric data.

This PMDA can be used with GFS2 filesystems which are both mounted as local filesystems and filesystems which are  mounted as shared storage  within a clustered environment. However there are some metrics which  specifically require GFS2 to be setup in a clustered environment to be  able to provide metric data. This is due to them expecting locking  messages to be passed via the distributed lock manager (DLM) between nodes of a cluster in order to generate their output.

These cluster-environment-only metrics can be distinguished by the inclusion of their corresponding control metrics so that they can be  optionally enabled or disabled on systems where they are not desired to be monitored or not supported.

pmstore(3) can be used to assign values to these control metrics in order to enable (1) or disable (0) them. This mechanism is also useful on distributions that do not currently  have full support for the GFS2 trace-points or provide older versions of  the GFS2 driver.  

Further details on clustering and GFS2 can be found at http://redhat.com

Installation

Install the GFS2 PMDA by using the Install script as root:

     # cd $PCP_PMDAS_DIR/gfs2
     # ./Install

To uninstall, do the following as root:

     # cd $PCP_PMDAS_DIR/gfs2
     # ./Remove

pmdagfs2 is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd when the agent is installed or removed.

Files

$PCP_PMDAS_DIR/gfs2/help

default help text file for the GFS2 metrics

$PCP_PMDAS_DIR/gfs2/Install

installation script for the pmdagfs2 agent

$PCP_PMDAS_DIR/gfs2/Remove

undo installation script for the pmdagfs2 agent

$PCP_LOG_DIR/pmcd/gfs2.log

default log file for error messages from pmdagfs2

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

pmcd(1), pmstore(1), and gfs2(5).

Info

PCP Performance Co-Pilot