envd(1M)envd(1M)NAMEenvd - system physical environment daemon
SYNOPSIS
configfile]
DESCRIPTION
The 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 environ‐
mental conditions currently recognized by are over-temperature and
chassis fan failure.
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 If no option was specified and the default configfile does
not exist, fails. A recommended default configfile is available in The
configfile (or is only examined when the daemon is started or when it
receives a signal to restart and re-initialize the daemon itself.
uses the message logging facility to log warning messages. If config‐
file specifies messages to be logged, the destination of the warning
messages is determined by the configuration of the facility of the dae‐
mon (see syslogd(1M) and syslog(3C) for details) and various priorities
defined below for the corresponding environmental events. Warning mes‐
sages are written to the console if is unable to send to
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.
Event Event lines consist of an event keyword and a
message indicator, separated by a colon Valid
event keywords are and Valid message indicators
are and An example is indicating that warning
messages are to be sent for the event.
Event keywords must start in the first column,
and only one event and one message indicator are
allowed on a given line.
Action Action lines can consist of a sequence of any
valid commands or pipelines. Lines from one
event line to the next event line, or to the end
of the file, are part of the action lines for the
preceding event, and are passed intact to the
shell to execute upon detecting the event. The
action for an event can span across several
lines, but the syntax of every line must be
understood by There are no default actions for
any events if no action lines are specified.
No parsing or syntax checking is performed on the
action lines; system administrators are responsi‐
ble for verifying the correctness of the action
syntax.
Comments Lines beginning with the character in the first
column are comment lines, and all characters up
to the subsequent new-line character are ignored.
Blank lines are ignored as comment lines.
Here is an example file:
Only users with appropriate privileges can invoke
Over-temperature and Fan Failure Handling
Over-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 tempera‐
ture ranges and fan states specific to your system configuration, refer
to any of the following documents for your system: or
┌───────────────────┬───────────────────────────────────────────┐
│State │ State Description │
├───────────────────┼───────────────────────────────────────────┤
│NORMAL │ Within normal operating temperature range │
│OVERTEMP_CRIT │ Temperature has exceeded the normal oper‐ │
│ │ ating range of the system, but is still │
│ │ within the operating limit of the hard‐ │
│ │ ware media. │
│OVERTEMP_EMERG │ Temperature has exceeded the maximum │
│ │ specified operating limit of hardware │
│ │ media; power loss is imminent. A minimum │
│ │ of about 60 seconds is guaranteed between │
│ │ the OVERTEMP_MID state and the │
│ │ OVERTEMP_POWERLOSS (power loss) state. │
│OVERTEMP_POWERLOSS │ Hardware will disconnect all power from │
│ │ all cards in the system chassis. │
│FAN_NORMAL │ All chassis fans are operating normally. │
│FANFAIL_CRIT │ One or more chassis fans have failed, but │
│ │ the system has enough redundant fans to │
│ │ allow continued operation while the │
│ │ failed fans are replaced. │
│FANFAIL_EMERG │ Chassis fan failures prevent continued │
│ │ operation of the system; power loss is │
│ │ imminent. │
│FANFAIL_POWERLOSS │ Hardware will disconnect all power from │
│ │ all cards in the system chassis. │
└───────────────────┴───────────────────────────────────────────┘
The priorities mapped to the environmental events are: (for and and
(for and
Any non-shutdown activities (e.g. file transfer) should be performed at
and It is important to configure only critical activities for because
the over-temperature might rise dramatically fast to It is recommended
to perform a quick shutdown using at and to preserve file system data
integrity. If the hardware enters the or 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 to or from to the warning message, if specified, is logged, and
the corresponding action is executed once, and only once, per state
change.
AUTHOR
was developed by HP.
FILES
executable file
default
configuration file
default
configuration file
work files
SEE ALSOreboot(1M), shutdown(1M), syslogd(1M), syslog(3C),
envd(1M)
