33.4 NFS Daemons

   

NFS uses a number of daemon processes to provide reliable file system access over a network. A number of clients may be accessing shared files, and it is the responsibility of the NFS system to guarantee file system integrity. NFS is a stateless server, which means that it does not keep a record of the state of files and clients that are accessing them. To keep consistency of files, a file locking mechanism is used through NFS daemons to ensure that files are properly locked when accessed by a client. Table 33-3 shows a list of NFS daemons and their functions on the client and server.

Table 33-3. NFS Daemons
Name NFS System Description
portmap Both client and server RPC daemon used in HP-UX 10.20 and earlier versions.
rpcbind Both client and server RPC daemon used in HP-UX 10.30 and later versions.
rpc.statd Both client and server RPC daemon used with the rpc.lockd daemon to provide crash recovery functions.
rpc.lockd Both client and server Used for file locking on both NFS servers and clients. Both client and server rpc.lockd daemons interact with each other to provide file locking functions.
nfsd Server The NFS server daemon. A number of server daemon processes (by default, 4) are started at startup time. All of these processes register themselves with portmap or rpcbind . A heavily loaded NFS server may start more daemon processes.
rpc.pcnfsd Server Used with PCNFS. Not required if all clients are UNIX machines.
rpc. mountd Server Keeps a record of mounted and exported file systems. Replies to mount requests .
biod Client Used to handle buffer cache in asynchronous I/O on NFS clients.

   
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HP Certified
HP Certified: HP-UX System Administration
ISBN: 0130183741
EAN: 2147483647
Year: 2000
Pages: 390
Authors: Rafeeq Rehman

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