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HP-UX Reference > Eenvd(1M)HP-UX 11i Version 2: December 2007 Update |
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NAMEenvd — system physical environment daemon DESCRIPTIONThe envd daemon provides a means for the system to respond to environmental conditions detected by hardware. Such responses are typically designed to maintain file system integrity and prevent data loss. The environmental conditions currently recognized by envd are over-temperature and chassis fan failure. envd logs messages and then executes actions when a supported environmental event is detected. Whether to do message logging and what actions to perform for a given environmental event are determined by configfile (default is /etc/envd.conf). If no -f option was specified and the default configfile /etc/envd.conf does not exist, envd fails. A recommended default configfile is available in /usr/newconfig/etc/envd.conf. The configfile (or /etc/envd.conf) is only examined when the daemon is started or when it receives a SIGHUP signal to restart and re-initialize the daemon itself. envd uses the syslog message logging facility to log warning messages. If configfile specifies messages to be logged, the destination of the warning messages is determined by the configuration of the LOG_DAEMON facility of the syslogd daemon (see syslogd(1M) and syslog(3C) for details) and various syslog priorities defined below for the corresponding environmental events. Warning messages are written to the console if envd is unable to send to syslogd. The configfile is composed of event lines, each of which followed by zero or more action lines. Comment lines can be interspersed at any point. No more than one event line can be specified for a given event.
Here is an example /etc/envd.conf file: # The example below configures envd to log the warning message and # to rcp critical applications to a remote machine at OVERTEMP_CRIT # or FANFAIL_CRIT. It configures envd to log emergency messages # and to perform system shutdown at OVERTEMP_EMERG or FANFAIL_CRIT, # in order to reserve data integrity. OVERTEMP_CRIT:y /usr/bin/rcp critical_appl_files \ remote_machine:/backup OVERTEMP_EMERG:y /usr/sbin/reboot -qh FANFAIL_CRIT:y /usr/bin/rcp critical_appl_files \ remote_machine:/backup FANFAIL_EMERG:y /usr/sbin/reboot -qh Only users with appropriate privileges can invoke envd. Over-temperature and Fan Failure HandlingOver-temperature and fan failure handling is supported only on systems equipped with appropriate sensing hardware. Over-temperature and fan failure limits vary, depending on the hardware. Each system processor defines its own thresholds for supported equipment combinations. The table below shows temperature and fan failure states. For the temperature ranges and fan states specific to your system configuration, refer to any of the following documents for your system: Site Planning and Preparation Guide, Installation and Configuration Guide, or Operator Handbook.
The syslog priorities mapped to the environmental events are: LOG_EMERG (for OVERTEMP_EMERG and FANFAIL_EMERG) and LOG_CRIT (for OVERTEMP_CRIT and FANFAIL_CRIT). Any non-shutdown activities (e.g. file transfer) should be performed at OVERTEMP_CRIT and FANFAIL_CRIT. It is important to configure only critical activities for OVERTEMP_CRIT because the over-temperature might rise dramatically fast to OVERTEMP_EMERG. It is recommended to perform a quick shutdown using /usr/sbin/reboot -qh at OVERTEMP_EMERG and FANFAIL_EMERG to preserve file system data integrity. If the hardware enters the OVERTEMP_POWERLOSS or FANFAIL_POWERLOSS state and the system has not been shut down, the sudden loss of power could result in data loss. Note that power-fail recovery functionality is not available in this case. When the hardware powers down, no warning messages are produced, and no action is taken by the system. Whenever an environmental state changes from one level to another (such as from NORMAL to OVERTEMP_CRIT or from FANFAIL_CRIT to FANFAIL_EMERG), the warning message, if specified, is logged, and the corresponding action is executed once, and only once, per state change. |
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