(4) Retain enough files on each client so that if separated from the
network it still can run a minimal useful set of Unix and NeXT facilities.
Tentatively, this would include all the facilities packaged with the
regular NextStation plus Mathematica. N ote that when connected to the
server, the directories containing these may be eclipsed by the
network-mounted directories.
File System Implementation
A server exports most subdirectories in its root directory. Each
of the clients mount these directories over the corresponding names.
Directories in /private are not exported or mounted, each station has its
own /private. If it is ever necessary to modify files in these
directories, this must be done at the server workstation or by
rlogin/telnet to it, and then with appropriate permissions.
Two server directories must be exported read/write:
- /usr/spool/mail holds mail for network userids.
- /Users contains the home directories of all network users.
Home directories will have names like:
- /Users/c123456
- /Users2/c123457
- ...etc...
This is exported read/write to the clients who mount it under the
corresponding name, /Net/muxxnx#/Users/. Some clients have their own
/Users directory. This allows user home directories to be stored on
multiple servers and even on client disks. The number (#) and the (xx) in
/Net/muxxnx#/Users directory should indicate which system contains it.
(e.g. /Net/muphnx3/Users is the /Users directory on machine number three
in the Physics cluster.)
Some file systems are mounted whole from the file server:
- /NextDeveloper
- /LocalApps
- /LocalLibrary
- /usr/include
- /usr/local
- /usr/games
The root system of a file server is mounted on each client as
/Net/apphost. Some major folders and several files are accessed via
symbolic links to the corresponding points in /Net/apphost. A list of
these is in /usr/local/mods/symlinks. This approach using symbolic links
allows those files deemed essential for the client to be accessed directly
on the client disk.
Things to come:
One performance improvement might be to duplicate some system folders and
even some frequently-used user folders (such as ~math175) to a second or
third file server. This second file server need not be a large-disk
system, just one with sufficient disk space. Network load would be the
same, but there'd be less queueing for files. This would require care in
keeping the duplicates syncronized.
Campus-Wide NeXT Network:
Logins are handled by NetInfo. See 02_Access. Sysadmins should
distinguish between file servers--any station can export files--and the
NetInfo servers.
Questions and comments concerning these policies should be directed to the NeXT Lab site consultant or the MU Campus Computing "NeXT Lab Co-ordinator", 882-5000.