Network lock manager

The network lock manager is a facility that works in cooperation with the Network File System (NFS) to provide a System V style of advisory file and record locking over the network.

The network lock manager (rpc.lockd) and the network status monitor (rpc.statd) are network-service daemons. The rpc.statd daemon is a user level process while the rpc.lockd daemon is implemented as a set of kernel threads (similar to the NFS server). Both daemons are essential to the ability of the kernel to provide fundamental network services.

  1. Mandatory or enforced locks are not supported over NFS.
  2. Network Lock Manager is specific to NFS Version 2 and Version 3.