NAME

       pmdazswap - zswap (compressed swap) PMDA

DESCRIPTION

       pmdazswap  is a Performance Metrics Domain Agent (PMDA) which exports metric values about compressed swap
       operation, as tracked by the zswap Linux kernel module.

       Zswap is a lightweight compressed cache for swap pages.  It takes pages that are in the process of  being
       swapped  out  and  attempts  to  compress them into a dynamically allocated RAM-based memory pool.  Zswap
       trades CPU cycles for potentially reduced swap I/O.  This tradeoff  can  also  result  in  a  performance
       improvement if reads from the compressed cache are faster than reads from a swap device.

       This  PMDA  exports metrics about pool size, number of pages stored, and various counters for the reasons
       pages are rejected.

INSTALLATION

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

             # cd $PCP_PMDAS_DIR/zswap
             # ./Install

       To uninstall, do the following as root:

             # cd $PCP_PMDAS_DIR/zswap
             # ./Remove

       pmdazswap 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/zswap/Install
           installation script for the pmdazswap agent

       $PCP_PMDAS_DIR/zswap/Remove
           undo installation script for the pmdazswap agent

       $PCP_LOG_DIR/pmcd/zswap.log
           default log file for error messages from pmdazswap

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) and pmcd(1).