NFS Server

The computer that makes the local file system accessible to users on the network.

NFS Client

The computer which accesses the file system that is made available by the NFS server.

rpc.mountd

A daemon that runs on NFS servers. It handles initial requests from NFS clients. NFS clients use the mount command to make requests.

rpc.nfsd/nfsd

A daemon that runs on NFS servers. It is formed of stateless kernel threads that handle most of the NFS requests (including NFS read/write requests) from NFS clients.

rpc.lockd/lockd

A daemon that runs on NFS servers and NFS clients.

On the server side, it receives lock requests from the NFS client and passes the requests to the kernel-based nfsd.

On the client side, it forwards the NFS lock requests from users to the rpc.lockd/lockd on the NFS server.

rpc.statd/statd

A daemon that runs on NFS servers and NFS clients.

On the server side, it maintains the information about NFS clients that have locks and NFS clients that are trying for locks. If the NFS server recovers after a crash, rpc.statd/statd notifies all the NFS clients to reclaim locks that they had before the server crash. This process is called NFS lock recovery.

On the client side, it maintains a list of servers for which users requested locks. It also processes notification from the server statd/rpc.statd. If the NFS client recovers after a crash, rpc.statd/statd notifies the NFS server to stop monitoring the client since the client restarted.

rpc.idmapd/nfsmapid

A userland daemon that maps the NFSv4 username and group to the local username and group of the system. This daemon is specific to NFSv4.

rpc.svcgssd

A userland daemon runs on NFS server. It provides rpcsec_gss security to the RPC daemons.

NFSv4

The latest version of NFS. It is a stateful protocol. NFXv4 requires only the rpc.nfsd/nfsd daemon to be running on the system. It does not require the associate daemons rpc.mountd, statd, and lockd.