lockd(NADM)

lockd -- network lock daemon

Synopsis

/usr/lib/nfs/lockd [-s] [-t timeout] [-g graceperiod] [-d] [-h hashsize] [-p proto] [-v provider] [-a]

Description

The lockd command processes lock requests that are either sent locally by the kernel or remotely by another lock daemon. lockd forwards lock requests for remote data to the server site's lock daemon through RPC/XDR. lockd then requests the status monitor daemon, statd(NADM), for monitor service. The reply to the lock request will not be 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, on the other hand, are notified by the status monitor daemon of the server recovery and promptly resubmit previously granted lock requests. If a lock daemon fails to secure a previously granted lock at the server site, then it sends SIGLOST to a process.

The lockd daemon is automatically invoked in run level 3.

Only a privileged user can execute this command.

Options

The following options are available to the lockd command:

-a: Start lockd using all available transports.
-d: Turn on debugging.
-g graceperiod: Use graceperiod seconds as the grace period duration instead of the default value (25 seconds).
-h hashsize: Use hashsize buckets in the hash table used to keep client handles.
-p proto: Start lockd only using the network selection protocol specified by proto.
-s: Report sharing conflicts.
-t timeout: Use timeout seconds as the interval instead of the default value (25 seconds) to retransmit lock request to the remote server.
-v provider: Start lockd only using the device specified by provider.

References

fcntl(S), lockf(S), nfsping(NC), signal(S), statd(NADM)