secondary linux server project

[Ben Luey <lueyb@carleton.edu>]

Here is what I think is not a unique situation: a small, poor non-profit
company has a bunch of old hardware and lacks much computer experience.
Some has or wants to setup a linux server for them that does internet
access, mail, samba and dns, etc,. , but because no one on-site knows
linux and the setup guy might be pretty busy, (s)he doesn't want to
make the company too dependent on one server running on old hardware. 

So I was thinking it would be really nice to scrap together a lowly 486
that would be a secondary server. It would be unnoticed on the network to
the clients, and only synchronize files with the real server when in
passive mode. If something dies on the real server, a user can just run a
script on the secondary computer (or have this done by the secondary
checking up on the primary) and it will for all appearances become the
primary computer (same ip). When the other computer is fixed, another
script can be run to resync the hard drive and put the secondary back in
passive mode.

My question is how much of this has already been made? Are there any
sources I should look at. What program would you recommend using this?
Etc.

I was thinking:

mkdir /etcactive  on secondary computer
and keep certain files in /etcserver on the secondary synced with the
primary (/etc/passwd, /etc/shadow, smb.conf, httpd.conf, named.* HOSTNAME,
etc)

for each file in /etcserver, have a file /etc/*.passive that would be
the etc files for passive mode. The script would then change all
the links in /etc from pointing to /etc/*.passive to /etcactive/* when
going into passive mode and visa versa. (would this be unnecessary if the
files were just synced (outside of HOSTNAME) and we used runlevels to keep
the services not running?)

Some secure way to syncing files that will not transfer files that haven't
been modified. Hopefully something that isn't very bandwidth intensive so
it could be updated everyone hour or so. 

This would cover bringup the secondary into active mode.

When the primary is fixed. Run a script on secondary to have it stop doing
all server task and use old ip and make its files accessible for resync.

Primary run a script to sync files.

Secondary run a script to un-make its files accessible and start syncing
with primary. Include some precaution to if scripts run it wrong order,
new data isn't overwritten with old data. (maybe data based and run xntpd
on the secondary?)

Anyone have any ideas on the best way to go about this, or want to help or
anything? 

Thanks,

Ben

Ben Luey
lueyb@carleton.edu
ICQ: 19144397

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