Using NFS Mounted Resources with Advanced Server/9000

NFS mounted resources can be shared like any other local resources on the AS/U server. However, you should exercise caution when using NFS mounted resources with AS/U. Please note the following risks and recommendations:

Read-only access to NFS mounts used with AS/U is strongly recommended to insure data integrity. AS/U will consider writes complete before they are actually written to the remote NFS server file system.
Root access must be enabled across NFS mounts when NFS mounts are used as shares in AS/U. AS/U initially creates a file as root and then changes the ownership to the appropriate user.
The special AS/U users (lmxadmin, lmworld, etc.) and groups (DOS---, etc.) must be configured on the system providing the NFS mounted resources. These will need to be created manually if AS/U is not installed on the system. AS/U may set the file ownership to one of these users or groups.
Ensure that the uids and gids in the /etc/passwd files on all systems match. This is necessary to ensure that HP-UX access permissions are interpreted correctly.




	CAUTION: The reliability of the AS/U server is only as good as the NFS mounts beneath it. If an NFS mount goes down, not only may data be lost, but any AS/U server process (lmx.srv) which is attempting to access the remote file system hangs. In such cases, all the clients associated with these processes may hang and new connection requests may fail. These lmx.srv processes will hang forever if the NFS mount is a hard mount. The lmx.srv process will eventually return if the NFS mount is a soft mount ; however, all client connections associated with the lmx.srv process may be dropped if the NFS timeout period (including retries and retransmissions) is longer than the session timeout parameter configured on the client for any clients associated with that lmx.srv process.

The UseNfsLocks and RootOwnsFilesCreatedOnNFS registry values are associated with NFS usage. The UseNfsLocks value is in effect only if UseUnixLocks is set to 1. It works as follows:

UseNfsLocks 1 The record locks on NFS files created by clients are reflected in the NFS file system. If this UNIX lock fails because the NFS lock manager is not running, then AS/U returns an error.
UseNfsLocks 0 The record locks created by clients on the NFS files are reflected in the NFS file system as in the previous case. But if this UNIX lock fails because the NFS lock manager is not running, then AS/U ignores that error and returns success status.

In most circumstances, the AS/U server will return an error if the lock request is not granted. The RootOwnsFilesCreatedOnNFS value is set to 1 by default and should not be changed.

Using NFS Mounted Resources with Advanced Server/9000

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