lockd is part of the NFS lock manager, which supports record locking operations on NFS files. See fcntl(2) and lockf(3C) . The lock manager provides two functions:
- it forwards fcntl(2) locking requests for NFS mounted file systems to the lock manager on the NFS server
- it generates local file locking operations in response to requests forwarded from lock managers running on NFS client machines.
State information kept by the lock manager about these locking requests can be lost if the lockd is killed or the operating system is rebooted. Some of this information can be recovered as follows. When the server lock manager restarts, it waits for a grace period for all client-site lock managers to submit reclaim requests. Client-site lock managers, on the other hand are notified by the status monitor daemon, statd(1M) , of the restart and promptly resubmit previously granted lock requests.