pcnfs(5) pcnfs(5)
NAME
pcnfs - extensions to support PCs in a Network File System (NFS) envi-
ronment
DESCRIPTION
DFS (MS-DOS) is a extension to NFS which allows personal computer (PC)
users to share files with and spool printing to remote machines that
support the DFS (MS-DOS) daemon [see pcnfsd(8)]. The following sec-
tions discuss DFS (MS-DOS) from a server standpoint in more detail.
Authentication
DFS (MS-DOS) enables a PC user to acquire a user identity for use dur-
ing DFS (MS-DOS) requests. The DFS (MS-DOS) netopen program accepts a
user name and password, encrypts them, and calls the authentication
server for the PC. When this procedure succeeds, it returns a userid
and a groupid, which will be used to construct credentials for the PC
user. Failure of this procedure indicates that the name and password
are unacceptable.
Requests from a PC which has not been provided a user identity via the
netopen program have the identity "nobody" (userid -2, groupid 0). A
user with this identity will only achieve limited access to the Reli-
ant UNIX file system. From the system administrator's perspective,
universal use of "nobody" privileges is less than ideal because it
becomes impossible to account for disk space usage on a server among
the different PC users.
Printing
DFS (MS-DOS) achieves print spooling using normal NFS file operations.
When a DOS printer is redirected to an NFS printer on a file server
with the DOS command,
PRINIT lpt1: \\host\printer
the netopen program calls the server to determine where spool files
should be placed.
DFS (MS-DOS) takes the name of the spool directory and mounts an NFS
virtual drive on it. The spool directory is determined on a per-server
basis via the argument passed to pcnfsd when it is invoked. DFS (MS-
DOS) then creates spool files in that directory. When DFS (MS-DOS)
determines that a file is to be printed, it calls the spooling service
with:
- the name of the file to be printed
- the name of the logged-in user on the PC
- the name of the printer to be used.
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pcnfs(5) pcnfs(5)
The DFS (MS-DOS) daemon then invokes the local spooler to print the
file.
NOTE
Since it simply invokes the standard print spooling subsystem, DFS
(MS-DOS) can be used with remote printers.
Troubleshooting
DFS (MS-DOS) users sometimes attribute difficulties with DFS (MS-DOS)
operations to network or server problems. The utilities netstat and
ping (on the PC) and netstat(1M) and nfsstat(1M) (on the server) can
help in troubleshooting these difficulties.
Make sure that the network is enabled on the server system that is
being accessed. If there are other users using DFS (MS-DOS) to access
the same server, then the network is working. Run ping(1M) on another
host on the network to verify that the network is enabled on the
server. From the server in question type the following:
ping hostname
where hostname is another host on the network. If a "Network down"
message is returned, it is possible that the network has been disabled
for that system.
LAN1 V3 does include the Reliant UNIX operating system ping utility.
LAN1 V3 does respond to ICMP echo requests. Users can therefore use
ping from a Reliant UNIX server to verify that the network is con-
nected. If the PC does not respond to the ping, the user should run
the netstat utility on the PC while executing ping. This will display
the number of ICMP requests received by the PC. If the number does not
increment, the PC interface might be faulty or the network might have
failed.
If no gateway has been designated (see LAN1 DFS (MS-DOS) V3.0
Administrator's Guide), Internet datagrams targeted for networks other
than the local net are not sent. The number of datagram transmissions
that fail in this way is displayed with the netstat command.
SEE ALSO
mountd(1M), netstat(1M), nfsd(1M), nfsstat(1M), ping(1M), icmp(7).
LAN1 DFS (MS-DOS) V3.0 Administrator's Guide.
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