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).