rpc.lockd(8) System Manager's Manual rpc.lockd(8)
NAME
rpc.lockd, lockd - Network lock daemon
SYNOPSIS
/usr/sbin/rpc.lockd [-b hostname] [-c] [-d debug] [-g graceperiod] [-h hashsize] [-s] [-t timeout]
OPTIONS
The default behavior will create and bind a socket for each protocol per interface on the system. When the -b switch is specified, one
socket per protocol will be created and bind to the passed IP address. Available only on TruCluster Server systems. This option starts the
clusterwide lock daemon, which helps provide highly available NFS service. Do not use -c directly. Highly available NFS service is config-
ured by default and typically does not require intervention. If you do need to start the clusterwide lock daemon, use the CAA command,
caa_start cluster_lockd.
For more information, see the TruCluster Server Administration manual. Internal Use Only. Use this option only under the direction
of technical support personnel. Causes the rpc.lockd daemon to use the variable graceperiod (in seconds) as the grace period dura-
tion instead of the default value of 15 seconds. Internal Use Only. Causes the rpc.lockd daemon to use the variable timeout (in
seconds) as the interval instead of the default value of 5 seconds to retransmit a lock request to the remote server.
DESCRIPTION
The rpc.lockd daemon processes lock requests that are either sent locally by the kernel or remotely by another lock daemon. The NFS locking
service makes this advisory locking support possible by using the fcntl system call and the lockf subroutine. The rpc.lockd daemon forwards
lock requests for remote data to the server site's lock daemon. The rpc.lockd daemon then requests the status monitor daemon, rpc.statd,
for monitor service. The reply to the lock request is not sent to the kernel until the status daemon and the server site's lock daemon have
replied.
If either the status monitor or server site's lock daemon is unavailable, the reply to a lock request for remote data is delayed until all
daemons become available.
When a server recovers, it waits for a grace period for all client site lock daemons to submit reclaim requests. Client site lock daemons
are notified by rpc.statd of the server recovery and promptly resubmit previously granted lock requests. If a client site's lock daemon
fails to secure previously granted locks at the server site, it sends the signal SIGLOST to all the processes that were previously holding
locks and cannot reclaim them.
SEE ALSO
Commands: rpc.statd(8)
Functions: fcntl(2), signal(2), lockf(3)
rpc.lockd(8)