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Date: Sun, 20 Aug 1995 12:22:29 -0500
To: hackers@freebsd.org
From: rkw@dataplex.net (Richard Wackerbarth)
Subject: Some thoughts on diskless systems, etc.
Sender: hackers-owner@freebsd.org
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I have been thinking about the problems associated with maintaining a group
of machines that should all be basically the same.

If we divide the filespace into a few chunks, they appear to fall into a
few categories.

1) Shared alterable  eg: /home, /usr/home, or whatever..
2) Shared readonly   eg: /usr/share
3) Local alterable   eg: /var
4) Local readonly    eg: /stand

Looking at the /usr directory, most of it should really be readonly.
The same is true on /bin.

If done properly, /etc would be readonly, but each machine might need its
own version. Things in there that need to change can be linked to /var/etc,
for example.

So here are my questions.

1) Why does "/" need to be r/w?
2) What do you think of the following:

PROPOSAL:
Modify "/sbin/init" to use a file in "/" (eg: "/rc") rather than "/etc/rc"
as its initial file.

IMPACTS:
That way I could start by "mount"ing my own private "/etc".  The default
could simply be a one-liner ". /etc/rc". Diskless systems (of the same
type) would all get the same "/" from their server. Their "/rc" would then
do something to mount the workstation's very small "/etc" filesystem, and
continue with common structure.

If I am doing backups, much of the base system is now on ronly media. I
need only back up my custom "/etc" files to be able to rebuild a system.

My working backups might also include "/var" or portions thereof, as well
as the home directories, etc.


Comments? Questions? Suggestions?

----
Richard Wackerbarth
rkw@dataplex.net