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37 .Nd host status monitoring daemon
48 is a daemon which co-operates with
50 daemons on other hosts to provide
51 a status monitoring service.
52 The daemon accepts requests from
53 programs running on the local host (typically,
55 the NFS file locking daemon) to monitor the status of specified
57 If a monitored host crashes and restarts, the remote daemon will
58 notify the local daemon, which in turn will notify the local program(s)
59 which requested the monitoring service.
60 Conversely, if this host crashes
61 and re-starts, when the
63 re-starts, it will notify all of the hosts which were being monitored
64 at the time of the crash.
66 The following option is available:
67 .Bl -tag -width indent
69 Cause debugging information to be written to syslog, recording
70 all RPC transactions to the daemon.
71 These messages are logged with level
72 LOG_DEBUG and facility LOG_DAEMON.
73 Error conditions are logged irrespective
74 of this option, using level LOG_ERR.
78 in the foreground, rather than going into daemon mode.
79 This is useful if some other process uses
85 and wants to monitor when and how it exits.
87 Specify specific IP addresses to bind to.
88 This option may be specified multiple times.
95 Note that when specifying IP addresses with
98 will automatically add
100 and if IPv6 is enabled,
106 option allow to force the daemon to bind to the specified
108 for both AF_INET and AF_INET6 address families.
113 utility must NOT be invoked by
115 because the protocol assumes that the daemon will run from system start time.
116 Instead, it should be run from
118 after the network has been started.
120 .Bl -tag -width /usr/include/rpcsvc/sm_inter.x -compact
121 .It Pa /var/db/statd.status
122 non-volatile record of currently monitored hosts.
123 .It Pa /usr/include/rpcsvc/sm_inter.x
124 RPC protocol specification used by local applications to register monitoring requests.
131 The implementation is based on the specification in X/Open CAE Specification
132 C218, "Protocols for X/Open PC Interworking: XNFS, Issue 4", ISBN 1 872630 66 9
134 There is no means for the daemon to tell when a monitored host has
135 disappeared permanently (e.g.\& catastrophic hardware failure), as opposed
136 to transient failure of the host or an intermediate router.
138 it will re-try notification attempts at frequent intervals for 10 minutes,
139 then hourly, and finally gives up after 24 hours.
141 The protocol requires that symmetric monitor requests are made to both
142 the local and remote daemon in order to establish a monitored relationship.
143 This is convenient for the NFS locking protocol, but probably reduces the
144 usefulness of the monitoring system for other applications.
146 The current implementation uses more than 1Kbyte per monitored host in
147 the status file (and also in VM).
148 This may be inefficient for NFS servers
149 with large numbers of clients.