# pmdalustre

## 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/";**
    
           See comments in the shipped **lustre.conf** file for further details.
           By default, this file is installed with everything commented (and
           so it has no effect unless edited) because the built-in heuristics
           used by **pmdalustre** should suffice.
    
           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 variables 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).
    


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