RPC.STATD(8) BSD System Manager's Manual RPC.STATD(8)
rpc.statd -- host status monitoring daemon
The rpc.statd utility is a daemon which co-operates with rpc.statd dae-
mons on other hosts to provide a status monitoring service. The daemon
accepts requests from programs running on the local host (typically,
rpc.lockd(8), the NFS file locking daemon) to monitor the status of spec-
ified hosts. If a monitored host crashes and restarts, the remote daemon
will notify the local daemon, which in turn will notify the local pro-
gram(s) which requested the monitoring service. Conversely, if this host
crashes and re-starts, when the rpc.statd re-starts, it will notify all
of the hosts which were being monitored at the time of the crash.
The following option is available:
-d Cause debugging information to be written to syslog, recording
all RPC transactions to the daemon. These messages are logged
with level LOG_DEBUG and facility LOG_DAEMON. Error conditions
are logged irrespective of this option, using level LOG_ERR.
-n Just send SM_NOTIFY messages to notify any hosts of a restart.
Do not start daemon.
The rpc.statd utility must NOT be invoked by inetd(8) because the proto-
col assumes that the daemon will run from system start time. Instead, it
should be run from rc(8) after the network has been started.
/var/db/statd.status non-volatile record of currently moni-
/usr/include/rpcsvc/sm_inter.x RPC protocol specification used by local
applications to register monitoring
syslog(3), rc(8), rpc.lockd(8)
There is no means for the daemon to tell when a monitored host has disap-
peared permanently (eg. catastrophic hardware failure), as opposed to
transient failure of the host or an intermediate router. At present, it
will re-try notification attempts at frequent intervals for 10 minutes,
then hourly, and finally gives up after 24 hours.
The protocol requires that symmetric monitor requests are made to both
the local and remote daemon in order to establish a monitored relation-
ship. This is convenient for the NFS locking protocol, but probably
reduces the usefulness of the monitoring system for other applications.
The current implementation uses more than 1Kbyte per monitored host in
the status file (and also in VM). This may be inefficient for NFS
servers with large numbers of clients.
The implementation is based on the specification in X/Open CAE Specifica-
tion C218, "Protocols for X/Open PC Interworking: XNFS, Issue 4", ISBN 1
872630 66 9
BSD September 19, 1995 BSD