4 These are some terms and symbols used in this document. Many are
5 explained in more detail later in the document.
7 Client, Client1, Client2, MDT, OST, MDS, OSS::
8 The entities exchanging messages. Clients are hosts mounting the
9 Lustre file system. The MDT and OST are services being provided by the
10 Lustre servers MDS and OSS.
13 A file or directory that is the object of a file system operation,
14 either on the namespace or on its data.
17 RPCs are exchanged in pairs (with a very few exceptions). The request
18 initiates the operation being carried out by the RPC pair.
21 The matching reply that completes an operation implemented by an RPC
25 An RPC pair that implements an operation that will change the
26 information on an MDT. See <<mds-reint-setattr-rpc>>.
29 An RPC pair that implements distributed locking across the servers and
30 clients. See <<ldlm-enqueue-rpc>>.
33 An RPC pair that provides information about extended attributes for a
34 resource. See <<mds-getxattr-rpc>>.
37 An RPC pair that sets resource attributes. See <<ost-setattr-rpc>>.
40 An RPC pair that assists with getting a lock back from an entity that
41 has it. See <<ldlm-bl-callback-rpc>>.
44 An RPC pair that notifies an entity that a requested lock is now
45 available. See <<ldlm-cp-callback-rpc>>.
48 An RPC pair that modifies the size attribute of a resource on an
49 OST. See <<ost-punch-rpc>>.
52 The first section (structure) of each RPC. It identifies which RPC
53 operation (opcode) the RPC conveys.