Previous topic |
Next topic |
Contents |
Contact z/OS |
Library |
PDF
Delegating management of a file's resources to an NFS client z/OS Network File System Guide and Reference SC23-6883-00 |
|
The NFS version 4 protocol enables an NFS Server to temporarily delegate management of a file's resources to an NFS Client. The key purpose of the delegation is to provide improved performance by eliminating communications with the NFS Server. When a file’s management is delegated to an NFS Client, all file access requests can be managed locally by the NFS Client while the file is delegated. Use the following NFS Server Site Attributes to control the activation of the delegation function:
A new Modify operator command, V4DELG=ON/OFF can be used to dynamically
turn on or off NFS Version 4 protocol file management delegation
to NFS clients.
File delegation is at the NFS Server’s discretion. When an NFS Client sends a file open request, the server determines whether to delegate the file or not. The NFS Client cannot assume that the file will be delegated. When the client has not contacted the server for a lease time interval, the server can remove all delegations to the client. If a local user or another client requests share reservations or access to the delegated file, the server will recall the delegated file. The NFS Server may recall the delegation at any time. The NFS Client must then send any modified data buffers and attributes back to the server. It should also send any locally established file locks to the server so that those locks can be established on the NFS Server to maintain the Client’s lock status over those files. When the delegation is granted to the client, the result is as
follows:
When the file is closed, the delegation returns back to the server. When another application on the z/OS system requires access to
the delegated file, the system must notify the NFS Server that the
delegation is being recalled. The server must then recall the file
from the delegated NFS Client(s). Any modified data buffers and file
attributes must be updated, and any necessary file locks must be established
before the recall can be completed. .The NFS server initiates a delegation
recall during the following circumstances:
Note:
|
Copyright IBM Corporation 1990, 2014
|