Multiple AS/U Server Access to NFS Files

By default, the file record lock information from one AS/U server will not be propagated to the others across NFS, so two servers can own a lock on the same file at the same time. Set the registry value UseUnixLocks to 1 to coordinate these locks through the NFS file system.

By default, the opportunistic lock information for an open file on one AS/U server will not be propagated to the other across NFS. So an AS/U server can open a file even though the file is already opened with oplock by another AS/U server. To prevent this from happening, disable the oplock option on the server. This can be done by setting the registry value UseOplocks to 0.

	NOTE: The default settings for the UseUnixLocks and UseOplocks keywords are chosen to optimize performance. Make the suggested changes only if you need file locking information to be propagated across NFS mounts or to other HP-UX applications running on the AS/U server.

The file open mode sharing information ( like DENY_ALL, DENY_WRITE, DENY_READ etc.) for an open file on one AS/U server will not be propagated to the other servers across NFS. So more than one server may open the NFS mounted file with a sharing mode like DENY_WRITE (which should not be allowed). To prevent problems from occurring, applications need to explicitly lock files when updating them rather than relying on the file open mode information to prevent other readers or writers.