Index for Section 8

Alphabetical listing for E

Bottom of page

esmd(8)
NAME
  esmd - Essential Services Monitor daemon

SYNOPSIS
  /usr/sbin/esmd [-a] [-r  retry_seconds]

OPTIONS
  -a  Limits the priority of any syslog messages posted by the ESM daemon to
      "alert." If this option is not specified, esmd will post an "emergency"
      message if it cannot restart a failed daemon, which may result in a
      message being sent to all users currently logged in to the system.  The
      -a option should only be used if the system administrator is actively
      monitoring syslogd messages.

  -r retry_seconds
      Specifies the interval between attempts to begin monitoring a daemon
      that has failed, and which esmd has been unable to restart
      automatically. The default period is 30 seconds. Specifying a period of
      zero disables retrying.

OPERANDS
  None.

DESCRIPTION
  The Essential Services Monitor (ESM) daemon, esmd, maintains the
  availability of essential system daemons by automatically restarting them
  if they terminate. The ESM daemon monitors the Event Manager daemon, evmd,
  and, in a cluster environment, the Cluster Application Availability (CAA)
  daemon, caad.

  The ESM daemon is started by the init process when the system is
  initialized to run level 2 and continues to run until the system is shut
  down or returned to single user mode. If the daemon terminates, it is
  restarted automatically by init.

  Configuration information is sent to the ESM daemon by a control program,
  /sbin/init.d/esm, which is run at key points in the startup and shutdown
  procedures. As startup or shutdown progresses, the control program updates
  the ESM state file, /var/run/esm.state and  signals the daemon to
  reconfigure itself.

  On startup, state transitions occur after evmd has started and, in a
  cluster environment, after caad has started.	On shutdown, transitions
  occur after each of these monitored daemons has terminated.  After each
  transition, the ESM daemon determines which of the monitored daemons should
  be running and adjusts its monitoring activities accordingly.

  The ESM daemon reports all state change information, including notice of
  failures and restarts, through the system logging daemon, syslogd. Messages
  are displayed on the system console during periods when syslogd is not
  running. See syslogd(8) for more information.

  If the ESM daemon fails to restart a monitored daemon, it reports the error
  by posting a high priority message through syslogd, and makes no further
  restart attempts. The system administrator should investigate the problem
  and restart the failed daemon. ESM periodically attempts to resume
  monitoring of the daemon, and posts an informational message when it
  succeeds.  If the monitored daemon fails again once monitoring has resumed,
  ESM will again make one attempt to restart it.

  ESM can be forced to restart a failed daemon by sending a SIGHUP signal to
  the esmd process.

  If there is a need to temporarily disable the ESM daemon for test purposes,
  to prevent the monitored daemons from being restarted automatically, send a
  SIGSTOP signal to esmd. To reactivate it, send a SIGCONT signal. The daemon
  should never be disabled on a production system.

NOTES
  If you want to use start options, you must add them to the esmd startup
  command in the /etc/inittab file.  The daemon reports any invalid start
  options with a single generic message through syslogd.

RESTRICTIONS
  The daemon terminates with an error message if it is started by any process
  other than init.

  The /sbin/init.d/esm program is intended to be run by the system startup
  and shutdown process and should not be run from the command line.

EXIT STATUS
  0 (Zero)
      Success.

  non 0
      An error occurred.

FILES
  /usr/sbin/esmd
      Executable file

  /sbin/init.d/esm
      Configuration control script

  /etc/inittab
      Initialization process control file

  /var/run/esm.state
      Monitoring state file

  /var/run/syslog.date/current/daemon.log
      Receives esmd status messages

SEE ALSO
  Commands: kill(1), caad(8), evmd(8), init(8), syslogd(8)

  Files: inittab(4)

Index for Section 8

Alphabetical listing for E

Top of page