Technical data

NFS Client
21.1 Key Concepts
Since a UNIX file system does not have a SYSTEM protection mask (the
superuser has all permissions for all files) the NFS client displays the SYSTEM
as identical to the OWNER mask.
21.1.6 Guidelines for Working with DNFS Devices
The following list summarizes the guidelines and restrictions associated with
DNFS devices:
• BACKUP and RESTORE operations
The OpenVMS NFS client does not emulate the on-disk structure of actual
OpenVMS disks. Therefore, applications that need direct knowledge of
the OpenVMS on-disk structure, such as image backup and restore, work
differently with DNFSn: volumes than with other volumes.
• File identification
The NFS client constructs OpenVMS file identifiers (FIDs) dynamically. The
remote NFS server does not store them. Each NFS client constructs its own
FIDs, possibly leading to different FIDs of the same file for different NFS
clients.
• Disk quotas
Disk quotas for OpenVMS disks are not applicable to DNFSn: disks.
21.1.7 How NFS Converts File Names
Because NFS uses UNIX style syntax for file names, valid OpenVMS file
names may be invalid on the NFS server and vice versa. The NFS software
automatically converts file names to the format required by either the client or
the server. (NFS always converts file names even when both the NFS client and
the NFS server are OpenVMS hosts.)
All name-mapping sequences on the OpenVMS client begin with the dollar sign
($) escape character. Appendix C lists the rules that govern these conversions
and provides a list of character sequences, server characters, and octal values
used for NFS name conversion.
21.2 NFS Client Startup and Shutdown
The NFS client can be shut down and started independently of TCP/IP Services.
This is useful when you change parameters or logical names that require the
service to be restarted.
The following files are provided:
• SYS$STARTUP:TCPIP$NFS_CLIENT_STARTUP.COM allows you to start up
the NFS client independently.
• SYS$STARTUP:TCPIP$NFS_CLIENT_SHUTDOWN.COM allows you to shut
down the NFS client independently.
To preserve site-specific parameter settings and commands, create the following
files. These files are not overwritten when you reinstall TCP/IP Services:
• SYS$STARTUP:TCPIP$NFS_CLIENT_SYSTARTUP.COM can be used as a
repository for site-specific definitions and parameters to be invoked when the
NFS client is started.
For example, use this file to store systemwide MOUNT commands.
NFS Client 21–5