Status: U
X-Lotus-FromDomain: STATOIL@INTERNET
From: "Lazaro Daniel Salem" <SALEM@statoil.com>
To: mw34@cornell.edu (Michael Wolfson)
Date: Tue, 8 Jun 1999 13:06:45 +0100
Mime-Version: 1.0

Hi Mike,
Maybe you want to consider the following additions to the Diskless NetBSD
HOWTO.  It is a kind of "poor man CDF" as used by HP-UX.

This is the results of some thoughts after I could not find any
sensitive information about clustering of my hp boxes (there was
clustering project in the NetBSD web server but that seems to be
dead). I posted something about this last year to the hp300 mailing
list but got not much ideas. Finally by "trial and error" I found my
way to it and later confirmed people were doing similar things with
linux boxes.

So here it is:

If in addition the both server and client(s) are running the same port
of NetBSD (e.g. when server and client(s) boxes are running the i386
port of the _same_ release of NetBSD) disk space can be saved by hard
linking the client's the /bin, /sbin and /lib directories to the
server's ones provided the client's file system is on the same device
as the server's root filesystem.

Even most of the configuration files under the clients /etc directory could
 be hard linked to the server ones modifying just a few (rc.config(5),
fstab(5), myname(5), exports(5) come to mind).  A less savvy but
simpler solution of separate /etc for each client. The kernel also
could be shared although you may want different tuned images for each
host (an NFS client has not the same requirements as an NFS server).

Strictly speaking, for the clients file systems you need only the
extra space required for their /var /tmp and /swap and some unique
config files under /etc . The rest might be shared (hard linked) with
the files in server's filesystem. Even under /var some of the sub
directories might be shared by several hosts. An example of that is
having a common /var/spool/mail for all the host in the domain.

The possibilities are many, choose the one it suits your needs best.

------------- End suggestions ----

I have done it myself to run two hp300 (340 and 425t from a 425t
server).  The diskless clients share the kernel, and the whole
directories /root /toor /bin /sbin /lib + some of the files under /etc
here and there. I have a shell script which I used to automate the
procedure of adding a new diskless client. I could send it to you for
use/improving/debugging.

Hope you find this interesting.
Lazaro